1 /********************* */
2 /*! \file theory_strings.cpp
4 ** Top contributors (to current version):
5 ** Andrew Reynolds, Tianyi Liang, Morgan Deters
6 ** This file is part of the CVC4 project.
7 ** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS
8 ** in the top-level source directory) and their institutional affiliations.
9 ** All rights reserved. See the file COPYING in the top-level source
10 ** directory for licensing information.\endverbatim
12 ** \brief Implementation of the theory of strings.
14 ** Implementation of the theory of strings.
17 #include "theory/strings/theory_strings.h"
21 #include "expr/kind.h"
22 #include "options/strings_options.h"
23 #include "smt/command.h"
24 #include "smt/logic_exception.h"
25 #include "smt/smt_statistics_registry.h"
26 #include "theory/ext_theory.h"
27 #include "theory/quantifiers/term_database.h"
28 #include "theory/rewriter.h"
29 #include "theory/strings/theory_strings_rewriter.h"
30 #include "theory/strings/type_enumerator.h"
31 #include "theory/theory_model.h"
32 #include "theory/valuation.h"
35 using namespace CVC4::context
;
36 using namespace CVC4::kind
;
42 std::ostream
& operator<<(std::ostream
& out
, Inference i
)
46 case INFER_SSPLIT_CST_PROP
: out
<< "S-Split(CST-P)-prop"; break;
47 case INFER_SSPLIT_VAR_PROP
: out
<< "S-Split(VAR)-prop"; break;
48 case INFER_LEN_SPLIT
: out
<< "Len-Split(Len)"; break;
49 case INFER_LEN_SPLIT_EMP
: out
<< "Len-Split(Emp)"; break;
50 case INFER_SSPLIT_CST_BINARY
: out
<< "S-Split(CST-P)-binary"; break;
51 case INFER_SSPLIT_CST
: out
<< "S-Split(CST-P)"; break;
52 case INFER_SSPLIT_VAR
: out
<< "S-Split(VAR)"; break;
53 case INFER_FLOOP
: out
<< "F-Loop"; break;
54 default: out
<< "?"; break;
59 std::ostream
& operator<<(std::ostream
& out
, InferStep s
)
63 case BREAK
: out
<< "break"; break;
64 case CHECK_INIT
: out
<< "check_init"; break;
65 case CHECK_CONST_EQC
: out
<< "check_const_eqc"; break;
66 case CHECK_EXTF_EVAL
: out
<< "check_extf_eval"; break;
67 case CHECK_CYCLES
: out
<< "check_cycles"; break;
68 case CHECK_FLAT_FORMS
: out
<< "check_flat_forms"; break;
69 case CHECK_NORMAL_FORMS_EQ
: out
<< "check_normal_forms_eq"; break;
70 case CHECK_NORMAL_FORMS_DEQ
: out
<< "check_normal_forms_deq"; break;
71 case CHECK_CODES
: out
<< "check_codes"; break;
72 case CHECK_LENGTH_EQC
: out
<< "check_length_eqc"; break;
73 case CHECK_EXTF_REDUCTION
: out
<< "check_extf_reduction"; break;
74 case CHECK_MEMBERSHIP
: out
<< "check_membership"; break;
75 case CHECK_CARDINALITY
: out
<< "check_cardinality"; break;
76 default: out
<< "?"; break;
81 Node
TheoryStrings::TermIndex::add( TNode n
, unsigned index
, TheoryStrings
* t
, Node er
, std::vector
< Node
>& c
) {
82 if( index
==n
.getNumChildren() ){
83 if( d_data
.isNull() ){
88 Assert( index
<n
.getNumChildren() );
89 TNode nir
= t
->getRepresentative( n
[index
] );
90 //if it is empty, and doing CONCAT, ignore
91 if( nir
==er
&& n
.getKind()==kind::STRING_CONCAT
){
92 return add( n
, index
+1, t
, er
, c
);
95 return d_children
[nir
].add( n
, index
+1, t
, er
, c
);
100 TheoryStrings::TheoryStrings(context::Context
* c
,
101 context::UserContext
* u
,
104 const LogicInfo
& logicInfo
)
105 : Theory(THEORY_STRINGS
, c
, u
, out
, valuation
, logicInfo
),
108 d_equalityEngine(d_notify
, c
, "theory::strings", true),
109 d_conflict(c
, false),
113 d_pregistered_terms_cache(u
),
114 d_registered_terms_cache(u
),
115 d_length_lemma_terms_cache(u
),
116 d_skolem_ne_reg_cache(u
),
119 d_extf_infer_cache(c
),
120 d_extf_infer_cache_u(u
),
121 d_ee_disequalities(c
),
124 d_proxy_var_to_length(u
),
126 d_has_extf(c
, false),
127 d_has_str_code(false),
128 d_regexp_memberships(c
),
131 d_pos_memberships(c
),
132 d_neg_memberships(c
),
135 d_processed_memberships(c
),
139 d_cardinality_lits(u
),
140 d_curr_cardinality(c
, 0),
141 d_strategy_init(false)
144 getExtTheory()->addFunctionKind(kind::STRING_SUBSTR
);
145 getExtTheory()->addFunctionKind(kind::STRING_STRIDOF
);
146 getExtTheory()->addFunctionKind(kind::STRING_ITOS
);
147 getExtTheory()->addFunctionKind(kind::STRING_STOI
);
148 getExtTheory()->addFunctionKind(kind::STRING_STRREPL
);
149 getExtTheory()->addFunctionKind(kind::STRING_STRCTN
);
150 getExtTheory()->addFunctionKind(kind::STRING_IN_REGEXP
);
151 getExtTheory()->addFunctionKind(kind::STRING_LEQ
);
152 getExtTheory()->addFunctionKind(kind::STRING_CODE
);
154 // The kinds we are treating as function application in congruence
155 d_equalityEngine
.addFunctionKind(kind::STRING_LENGTH
);
156 d_equalityEngine
.addFunctionKind(kind::STRING_CONCAT
);
157 d_equalityEngine
.addFunctionKind(kind::STRING_IN_REGEXP
);
158 d_equalityEngine
.addFunctionKind(kind::STRING_CODE
);
159 if( options::stringLazyPreproc() ){
160 d_equalityEngine
.addFunctionKind(kind::STRING_STRCTN
);
161 d_equalityEngine
.addFunctionKind(kind::STRING_LEQ
);
162 d_equalityEngine
.addFunctionKind(kind::STRING_SUBSTR
);
163 d_equalityEngine
.addFunctionKind(kind::STRING_ITOS
);
164 d_equalityEngine
.addFunctionKind(kind::STRING_STOI
);
165 d_equalityEngine
.addFunctionKind(kind::STRING_STRIDOF
);
166 d_equalityEngine
.addFunctionKind(kind::STRING_STRREPL
);
169 d_zero
= NodeManager::currentNM()->mkConst( Rational( 0 ) );
170 d_one
= NodeManager::currentNM()->mkConst( Rational( 1 ) );
171 d_neg_one
= NodeManager::currentNM()->mkConst(Rational(-1));
172 d_emptyString
= NodeManager::currentNM()->mkConst( ::CVC4::String("") );
173 std::vector
< Node
> nvec
;
174 d_emptyRegexp
= NodeManager::currentNM()->mkNode( kind::REGEXP_EMPTY
, nvec
);
175 d_true
= NodeManager::currentNM()->mkConst( true );
176 d_false
= NodeManager::currentNM()->mkConst( false );
179 if (options::stdPrintASCII())
185 TheoryStrings::~TheoryStrings() {
186 for( std::map
< Node
, EqcInfo
* >::iterator it
= d_eqc_info
.begin(); it
!= d_eqc_info
.end(); ++it
){
191 Node
TheoryStrings::getRepresentative( Node t
) {
192 if( d_equalityEngine
.hasTerm( t
) ){
193 return d_equalityEngine
.getRepresentative( t
);
199 bool TheoryStrings::hasTerm( Node a
){
200 return d_equalityEngine
.hasTerm( a
);
203 bool TheoryStrings::areEqual( Node a
, Node b
){
206 }else if( hasTerm( a
) && hasTerm( b
) ){
207 return d_equalityEngine
.areEqual( a
, b
);
213 bool TheoryStrings::areDisequal( Node a
, Node b
){
217 if( hasTerm( a
) && hasTerm( b
) ) {
218 Node ar
= d_equalityEngine
.getRepresentative( a
);
219 Node br
= d_equalityEngine
.getRepresentative( b
);
220 return ( ar
!=br
&& ar
.isConst() && br
.isConst() ) || d_equalityEngine
.areDisequal( ar
, br
, false );
222 Node ar
= getRepresentative( a
);
223 Node br
= getRepresentative( b
);
224 return ar
!=br
&& ar
.isConst() && br
.isConst();
229 bool TheoryStrings::areCareDisequal( TNode x
, TNode y
) {
230 Assert( d_equalityEngine
.hasTerm(x
) );
231 Assert( d_equalityEngine
.hasTerm(y
) );
232 if( d_equalityEngine
.isTriggerTerm(x
, THEORY_STRINGS
) && d_equalityEngine
.isTriggerTerm(y
, THEORY_STRINGS
) ){
233 TNode x_shared
= d_equalityEngine
.getTriggerTermRepresentative(x
, THEORY_STRINGS
);
234 TNode y_shared
= d_equalityEngine
.getTriggerTermRepresentative(y
, THEORY_STRINGS
);
235 EqualityStatus eqStatus
= d_valuation
.getEqualityStatus(x_shared
, y_shared
);
236 if( eqStatus
==EQUALITY_FALSE_AND_PROPAGATED
|| eqStatus
==EQUALITY_FALSE
|| eqStatus
==EQUALITY_FALSE_IN_MODEL
){
243 Node
TheoryStrings::getLengthExp( Node t
, std::vector
< Node
>& exp
, Node te
){
244 Assert( areEqual( t
, te
) );
245 Node lt
= mkLength( te
);
247 // use own length if it exists, leads to shorter explanation
250 EqcInfo
* ei
= getOrMakeEqcInfo( t
, false );
251 Node length_term
= ei
? ei
->d_length_term
: Node::null();
252 if( length_term
.isNull() ){
253 //typically shouldnt be necessary
256 Debug("strings") << "TheoryStrings::getLengthTerm " << t
<< " is " << length_term
<< std::endl
;
257 addToExplanation( length_term
, te
, exp
);
258 return Rewriter::rewrite( NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, length_term
) );
262 Node
TheoryStrings::getLength( Node t
, std::vector
< Node
>& exp
) {
263 return getLengthExp( t
, exp
, t
);
266 void TheoryStrings::setMasterEqualityEngine(eq::EqualityEngine
* eq
) {
267 d_equalityEngine
.setMasterEqualityEngine(eq
);
270 void TheoryStrings::addSharedTerm(TNode t
) {
271 Debug("strings") << "TheoryStrings::addSharedTerm(): "
272 << t
<< " " << t
.getType().isBoolean() << endl
;
273 d_equalityEngine
.addTriggerTerm(t
, THEORY_STRINGS
);
274 Debug("strings") << "TheoryStrings::addSharedTerm() finished" << std::endl
;
277 EqualityStatus
TheoryStrings::getEqualityStatus(TNode a
, TNode b
) {
278 if( d_equalityEngine
.hasTerm(a
) && d_equalityEngine
.hasTerm(b
) ){
279 if (d_equalityEngine
.areEqual(a
, b
)) {
280 // The terms are implied to be equal
281 return EQUALITY_TRUE
;
283 if (d_equalityEngine
.areDisequal(a
, b
, false)) {
284 // The terms are implied to be dis-equal
285 return EQUALITY_FALSE
;
288 return EQUALITY_UNKNOWN
;
291 void TheoryStrings::propagate(Effort e
) {
292 // direct propagation now
295 bool TheoryStrings::propagate(TNode literal
) {
296 Debug("strings-propagate") << "TheoryStrings::propagate(" << literal
<< ")" << std::endl
;
297 // If already in conflict, no more propagation
299 Debug("strings-propagate") << "TheoryStrings::propagate(" << literal
<< "): already in conflict" << std::endl
;
303 bool ok
= d_out
->propagate(literal
);
311 void TheoryStrings::explain(TNode literal
, std::vector
<TNode
>& assumptions
) {
312 Debug("strings-explain") << "Explain " << literal
<< " " << d_conflict
<< std::endl
;
313 bool polarity
= literal
.getKind() != kind::NOT
;
314 TNode atom
= polarity
? literal
: literal
[0];
315 unsigned ps
= assumptions
.size();
316 std::vector
< TNode
> tassumptions
;
317 if (atom
.getKind() == kind::EQUAL
) {
318 if( atom
[0]!=atom
[1] ){
319 Assert( hasTerm( atom
[0] ) );
320 Assert( hasTerm( atom
[1] ) );
321 d_equalityEngine
.explainEquality(atom
[0], atom
[1], polarity
, tassumptions
);
324 d_equalityEngine
.explainPredicate(atom
, polarity
, tassumptions
);
326 for( unsigned i
=0; i
<tassumptions
.size(); i
++ ){
327 if( std::find( assumptions
.begin(), assumptions
.end(), tassumptions
[i
] )==assumptions
.end() ){
328 assumptions
.push_back( tassumptions
[i
] );
331 if (Debug
.isOn("strings-explain-debug"))
333 Debug("strings-explain-debug") << "Explanation for " << literal
<< " was "
335 for (unsigned i
= ps
; i
< assumptions
.size(); i
++)
337 Debug("strings-explain-debug") << " " << assumptions
[i
] << std::endl
;
342 Node
TheoryStrings::explain( TNode literal
){
343 Debug("strings-explain") << "explain called on " << literal
<< std::endl
;
344 std::vector
< TNode
> assumptions
;
345 explain( literal
, assumptions
);
346 if( assumptions
.empty() ){
348 }else if( assumptions
.size()==1 ){
349 return assumptions
[0];
351 return NodeManager::currentNM()->mkNode( kind::AND
, assumptions
);
355 bool TheoryStrings::getCurrentSubstitution( int effort
, std::vector
< Node
>& vars
,
356 std::vector
< Node
>& subs
, std::map
< Node
, std::vector
< Node
> >& exp
) {
357 Trace("strings-subs") << "getCurrentSubstitution, effort = " << effort
<< std::endl
;
358 for( unsigned i
=0; i
<vars
.size(); i
++ ){
360 Trace("strings-subs") << " get subs for " << n
<< "..." << std::endl
;
363 Node mv
= d_valuation
.getModel()->getRepresentative( n
);
364 Trace("strings-subs") << " model val : " << mv
<< std::endl
;
365 subs
.push_back( mv
);
367 Node nr
= getRepresentative( n
);
368 std::map
< Node
, Node
>::iterator itc
= d_eqc_to_const
.find( nr
);
369 if( itc
!=d_eqc_to_const
.end() ){
370 //constant equivalence classes
371 Trace("strings-subs") << " constant eqc : " << d_eqc_to_const_exp
[nr
] << " " << d_eqc_to_const_base
[nr
] << " " << nr
<< std::endl
;
372 subs
.push_back( itc
->second
);
373 if( !d_eqc_to_const_exp
[nr
].isNull() ){
374 exp
[n
].push_back( d_eqc_to_const_exp
[nr
] );
376 if( !d_eqc_to_const_base
[nr
].isNull() ){
377 addToExplanation( n
, d_eqc_to_const_base
[nr
], exp
[n
] );
379 }else if( effort
>=1 && effort
<3 && n
.getType().isString() ){
381 Node ns
= getNormalString( d_normal_forms_base
[nr
], exp
[n
] );
382 subs
.push_back( ns
);
383 Trace("strings-subs") << " normal eqc : " << ns
<< " " << d_normal_forms_base
[nr
] << " " << nr
<< std::endl
;
384 if( !d_normal_forms_base
[nr
].isNull() ) {
385 addToExplanation( n
, d_normal_forms_base
[nr
], exp
[n
] );
389 //Trace("strings-subs") << " representative : " << nr << std::endl;
390 //addToExplanation( n, nr, exp[n] );
391 //subs.push_back( nr );
399 int TheoryStrings::getReduction( int effort
, Node n
, Node
& nr
) {
400 //determine the effort level to process the extf at
401 // 0 - at assertion time, 1+ - after no other reduction is applicable
402 Assert( d_extf_info_tmp
.find( n
)!=d_extf_info_tmp
.end() );
403 if( d_extf_info_tmp
[n
].d_model_active
){
405 int pol
= d_extf_info_tmp
[n
].d_pol
;
406 if( n
.getKind()==kind::STRING_STRCTN
){
413 std::vector
< Node
> lexp
;
414 Node lenx
= getLength( x
, lexp
);
415 Node lens
= getLength( s
, lexp
);
416 if( areEqual( lenx
, lens
) ){
417 Trace("strings-extf-debug") << " resolve extf : " << n
<< " based on equal lengths disequality." << std::endl
;
418 //we can reduce to disequality when lengths are equal
419 if( !areDisequal( x
, s
) ){
420 lexp
.push_back( lenx
.eqNode(lens
) );
421 lexp
.push_back( n
.negate() );
422 Node xneqs
= x
.eqNode(s
).negate();
423 sendInference( lexp
, xneqs
, "NEG-CTN-EQL", true );
432 if( options::stringLazyPreproc() ){
433 if( n
.getKind()==kind::STRING_SUBSTR
){
435 }else if( n
.getKind()!=kind::STRING_IN_REGEXP
){
440 if( effort
==r_effort
){
441 Node c_n
= pol
==-1 ? n
.negate() : n
;
442 if( d_preproc_cache
.find( c_n
)==d_preproc_cache
.end() ){
443 d_preproc_cache
[ c_n
] = true;
444 Trace("strings-process-debug") << "Process reduction for " << n
<< ", pol = " << pol
<< std::endl
;
445 Kind k
= n
.getKind();
446 if (k
== kind::STRING_STRCTN
&& pol
== 1)
450 //positive contains reduces to a equality
451 Node sk1
= mkSkolemCached( x
, s
, sk_id_ctn_pre
, "sc1" );
452 Node sk2
= mkSkolemCached( x
, s
, sk_id_ctn_post
, "sc2" );
453 Node eq
= Rewriter::rewrite( x
.eqNode( mkConcat( sk1
, s
, sk2
) ) );
454 std::vector
< Node
> exp_vec
;
455 exp_vec
.push_back( n
);
456 sendInference( d_empty_vec
, exp_vec
, eq
, "POS-CTN", true );
457 //we've reduced this n
458 Trace("strings-extf-debug") << " resolve extf : " << n
<< " based on positive contain reduction." << std::endl
;
461 else if (k
!= kind::STRING_CODE
)
463 Assert(k
== STRING_SUBSTR
|| k
== STRING_STRCTN
|| k
== STRING_STRIDOF
466 || k
== STRING_STRREPL
468 std::vector
< Node
> new_nodes
;
469 Node res
= d_preproc
.simplify( n
, new_nodes
);
471 new_nodes
.push_back( NodeManager::currentNM()->mkNode( kind::EQUAL
, res
, n
) );
472 Node nnlem
= new_nodes
.size()==1 ? new_nodes
[0] : NodeManager::currentNM()->mkNode( kind::AND
, new_nodes
);
473 nnlem
= Rewriter::rewrite( nnlem
);
474 Trace("strings-red-lemma") << "Reduction_" << effort
<< " lemma : " << nnlem
<< std::endl
;
475 Trace("strings-red-lemma") << "...from " << n
<< std::endl
;
476 sendInference( d_empty_vec
, nnlem
, "Reduction", true );
477 //we've reduced this n
478 Trace("strings-extf-debug") << " resolve extf : " << n
<< " based on reduction." << std::endl
;
489 /////////////////////////////////////////////////////////////////////////////
491 /////////////////////////////////////////////////////////////////////////////
494 void TheoryStrings::presolve() {
495 Debug("strings-presolve") << "TheoryStrings::Presolving : get fmf options " << (options::stringFMF() ? "true" : "false") << std::endl
;
496 initializeStrategy();
500 /////////////////////////////////////////////////////////////////////////////
502 /////////////////////////////////////////////////////////////////////////////
504 bool TheoryStrings::collectModelInfo(TheoryModel
* m
)
506 Trace("strings-model") << "TheoryStrings : Collect model info" << std::endl
;
507 Trace("strings-model") << "TheoryStrings : assertEqualityEngine." << std::endl
;
509 //AJR : no use doing this since we cannot preregister terms with finite types that don't belong to strings.
510 // change this if we generalize to sequences.
512 // Compute terms appearing in assertions and shared terms
513 //computeRelevantTerms(termSet);
514 //m->assertEqualityEngine( &d_equalityEngine, &termSet );
516 if (!m
->assertEqualityEngine(&d_equalityEngine
))
521 NodeManager
* nm
= NodeManager::currentNM();
523 std::vector
< Node
> nodes
;
524 getEquivalenceClasses( nodes
);
525 std::map
< Node
, Node
> processed
;
526 std::vector
< std::vector
< Node
> > col
;
527 std::vector
< Node
> lts
;
528 separateByLength( nodes
, col
, lts
);
529 //step 1 : get all values for known lengths
530 std::vector
< Node
> lts_values
;
531 std::map
< unsigned, bool > values_used
;
532 for( unsigned i
=0; i
<col
.size(); i
++ ) {
533 Trace("strings-model") << "Checking length for {";
534 for( unsigned j
=0; j
<col
[i
].size(); j
++ ) {
536 Trace("strings-model") << ", ";
538 Trace("strings-model") << col
[i
][j
];
540 Trace("strings-model") << " } (length is " << lts
[i
] << ")" << std::endl
;
541 if( lts
[i
].isConst() ) {
542 lts_values
.push_back( lts
[i
] );
543 Assert(lts
[i
].getConst
<Rational
>() <= RMAXINT
, "Exceeded LONG_MAX in string model");
544 unsigned lvalue
= lts
[i
].getConst
<Rational
>().getNumerator().toUnsignedInt();
545 values_used
[ lvalue
] = true;
547 //get value for lts[i];
548 if( !lts
[i
].isNull() ){
549 Node v
= d_valuation
.getModelValue(lts
[i
]);
550 Trace("strings-model") << "Model value for " << lts
[i
] << " is " << v
<< std::endl
;
551 lts_values
.push_back( v
);
552 Assert(v
.getConst
<Rational
>() <= RMAXINT
, "Exceeded LONG_MAX in string model");
553 unsigned lvalue
= v
.getConst
<Rational
>().getNumerator().toUnsignedInt();
554 values_used
[ lvalue
] = true;
556 //Trace("strings-model-warn") << "No length for eqc " << col[i][0] << std::endl;
558 lts_values
.push_back( Node::null() );
562 ////step 2 : assign arbitrary values for unknown lengths?
563 // confirmed by calculus invariant, see paper
564 Trace("strings-model") << "Assign to equivalence classes..." << std::endl
;
565 std::map
<Node
, Node
> pure_eq_assign
;
566 //step 3 : assign values to equivalence classes that are pure variables
567 for( unsigned i
=0; i
<col
.size(); i
++ ){
568 std::vector
< Node
> pure_eq
;
569 Trace("strings-model") << "The equivalence classes ";
570 for (const Node
& eqc
: col
[i
])
572 Trace("strings-model") << eqc
<< " ";
573 //check if col[i][j] has only variables
576 Assert(d_normal_forms
.find(eqc
) != d_normal_forms
.end());
577 if (d_normal_forms
[eqc
].size() == 1)
579 // does it have a code and the length of these equivalence classes are
581 if (d_has_str_code
&& lts_values
[i
] == d_one
)
583 EqcInfo
* eip
= getOrMakeEqcInfo(eqc
, false);
584 if (eip
&& !eip
->d_code_term
.get().isNull())
586 // its value must be equal to its code
587 Node ct
= nm
->mkNode(kind::STRING_CODE
, eip
->d_code_term
.get());
588 Node ctv
= d_valuation
.getModelValue(ct
);
590 ctv
.getConst
<Rational
>().getNumerator().toUnsignedInt();
591 Trace("strings-model") << "(code: " << cvalue
<< ") ";
592 std::vector
<unsigned> vec
;
593 vec
.push_back(String::convertCodeToUnsignedInt(cvalue
));
594 Node mv
= nm
->mkConst(String(vec
));
595 pure_eq_assign
[eqc
] = mv
;
596 m
->getEqualityEngine()->addTerm(mv
);
599 pure_eq
.push_back(eqc
);
604 processed
[eqc
] = eqc
;
607 Trace("strings-model") << "have length " << lts_values
[i
] << std::endl
;
609 //assign a new length if necessary
610 if( !pure_eq
.empty() ){
611 if( lts_values
[i
].isNull() ){
612 // start with length two (other lengths have special precendence)
614 while( values_used
.find( lvalue
)!=values_used
.end() ){
617 Trace("strings-model") << "*** Decide to make length of " << lvalue
<< std::endl
;
618 lts_values
[i
] = nm
->mkConst(Rational(lvalue
));
619 values_used
[ lvalue
] = true;
621 Trace("strings-model") << "Need to assign values of length " << lts_values
[i
] << " to equivalence classes ";
622 for( unsigned j
=0; j
<pure_eq
.size(); j
++ ){
623 Trace("strings-model") << pure_eq
[j
] << " ";
625 Trace("strings-model") << std::endl
;
627 //use type enumerator
628 Assert(lts_values
[i
].getConst
<Rational
>() <= RMAXINT
, "Exceeded LONG_MAX in string model");
629 StringEnumeratorLength
sel(lts_values
[i
].getConst
<Rational
>().getNumerator().toUnsignedInt());
630 for (const Node
& eqc
: pure_eq
)
633 std::map
<Node
, Node
>::iterator itp
= pure_eq_assign
.find(eqc
);
634 if (itp
== pure_eq_assign
.end())
636 Assert( !sel
.isFinished() );
638 while (m
->hasTerm(c
))
641 Assert(!sel
.isFinished());
650 Trace("strings-model") << "*** Assigned constant " << c
<< " for "
653 if (!m
->assertEquality(eqc
, c
, true))
660 Trace("strings-model") << "String Model : Pure Assigned." << std::endl
;
661 //step 4 : assign constants to all other equivalence classes
662 for( unsigned i
=0; i
<nodes
.size(); i
++ ){
663 if( processed
.find( nodes
[i
] )==processed
.end() ){
664 Assert( d_normal_forms
.find( nodes
[i
] )!=d_normal_forms
.end() );
665 Trace("strings-model") << "Construct model for " << nodes
[i
] << " based on normal form ";
666 for( unsigned j
=0; j
<d_normal_forms
[nodes
[i
]].size(); j
++ ) {
667 if( j
>0 ) Trace("strings-model") << " ++ ";
668 Trace("strings-model") << d_normal_forms
[nodes
[i
]][j
];
669 Node r
= getRepresentative( d_normal_forms
[nodes
[i
]][j
] );
670 if( !r
.isConst() && processed
.find( r
)==processed
.end() ){
671 Trace("strings-model") << "(UNPROCESSED)";
674 Trace("strings-model") << std::endl
;
675 std::vector
< Node
> nc
;
676 for( unsigned j
=0; j
<d_normal_forms
[nodes
[i
]].size(); j
++ ) {
677 Node r
= getRepresentative( d_normal_forms
[nodes
[i
]][j
] );
678 Assert( r
.isConst() || processed
.find( r
)!=processed
.end() );
679 nc
.push_back(r
.isConst() ? r
: processed
[r
]);
681 Node cc
= mkConcat( nc
);
682 Assert( cc
.getKind()==kind::CONST_STRING
);
683 Trace("strings-model") << "*** Determined constant " << cc
<< " for " << nodes
[i
] << std::endl
;
684 processed
[nodes
[i
]] = cc
;
685 if (!m
->assertEquality(nodes
[i
], cc
, true))
691 //Trace("strings-model") << "String Model : Assigned." << std::endl;
692 Trace("strings-model") << "String Model : Finished." << std::endl
;
696 /////////////////////////////////////////////////////////////////////////////
698 /////////////////////////////////////////////////////////////////////////////
701 void TheoryStrings::preRegisterTerm(TNode n
) {
702 if( d_pregistered_terms_cache
.find(n
) == d_pregistered_terms_cache
.end() ) {
703 d_pregistered_terms_cache
.insert(n
);
704 Trace("strings-preregister")
705 << "TheoryString::preregister : " << n
<< std::endl
;
706 //check for logic exceptions
707 Kind k
= n
.getKind();
708 if( !options::stringExp() ){
709 if (k
== kind::STRING_STRIDOF
|| k
== kind::STRING_ITOS
710 || k
== kind::STRING_STOI
711 || k
== kind::STRING_STRREPL
712 || k
== kind::STRING_STRCTN
715 std::stringstream ss
;
716 ss
<< "Term of kind " << k
717 << " not supported in default mode, try --strings-exp";
718 throw LogicException(ss
.str());
724 d_equalityEngine
.addTriggerEquality(n
);
727 case kind::STRING_IN_REGEXP
: {
728 d_out
->requirePhase(n
, true);
729 d_equalityEngine
.addTriggerPredicate(n
);
730 d_equalityEngine
.addTerm(n
[0]);
731 d_equalityEngine
.addTerm(n
[1]);
736 TypeNode tn
= n
.getType();
737 if (tn
.isRegExp() && n
.isVar())
739 std::stringstream ss
;
740 ss
<< "Regular expression variables are not supported.";
741 throw LogicException(ss
.str());
743 if( tn
.isString() ) {
744 // if finite model finding is enabled,
745 // then we minimize the length of this term if it is a variable
746 // but not an internally generated Skolem, or a term that does
747 // not belong to this theory.
748 if (options::stringFMF()
749 && (n
.isVar() ? d_all_skolems
.find(n
) == d_all_skolems
.end()
750 : kindToTheoryId(k
) != THEORY_STRINGS
))
752 d_input_vars
.insert(n
);
754 d_equalityEngine
.addTerm(n
);
755 } else if (tn
.isBoolean()) {
756 // Get triggered for both equal and dis-equal
757 d_equalityEngine
.addTriggerPredicate(n
);
759 // Function applications/predicates
760 d_equalityEngine
.addTerm(n
);
761 if( options::stringExp() ){
762 //collect extended functions here: some may not be asserted to strings (such as those with return type Int),
763 // but we need to record them so they are treated properly
764 getExtTheory()->registerTermRec( n
);
767 //concat terms do not contribute to theory combination? TODO: verify
768 if (n
.hasOperator() && kindToTheoryId(k
) == THEORY_STRINGS
769 && k
!= kind::STRING_CONCAT
)
771 d_functionsTerms
.push_back( n
);
778 Node
TheoryStrings::expandDefinition(LogicRequest
&logicRequest
, Node node
) {
779 Trace("strings-exp-def") << "TheoryStrings::expandDefinition : " << node
<< std::endl
;
784 void TheoryStrings::check(Effort e
) {
785 if (done() && e
<EFFORT_FULL
) {
789 TimerStat::CodeTimer
checkTimer(d_checkTime
);
794 if( !done() && !hasTerm( d_emptyString
) ) {
795 preRegisterTerm( d_emptyString
);
798 // Trace("strings-process") << "Theory of strings, check : " << e << std::endl;
799 Trace("strings-check") << "Theory of strings, check : " << e
<< std::endl
;
800 while ( !done() && !d_conflict
) {
801 // Get all the assertions
802 Assertion assertion
= get();
803 TNode fact
= assertion
.assertion
;
805 Trace("strings-assertion") << "get assertion: " << fact
<< endl
;
806 polarity
= fact
.getKind() != kind::NOT
;
807 atom
= polarity
? fact
: fact
[0];
809 //assert pending fact
810 assertPendingFact( atom
, polarity
, fact
);
814 Assert(d_strategy_init
);
815 std::map
<Effort
, std::pair
<unsigned, unsigned> >::iterator itsr
=
816 d_strat_steps
.find(e
);
817 if (!d_conflict
&& !d_valuation
.needCheck() && itsr
!= d_strat_steps
.end())
819 Trace("strings-check") << "Theory of strings " << e
<< " effort check "
821 if(Trace
.isOn("strings-eqc")) {
822 for( unsigned t
=0; t
<2; t
++ ) {
823 eq::EqClassesIterator eqcs2_i
= eq::EqClassesIterator( &d_equalityEngine
);
824 Trace("strings-eqc") << (t
==0 ? "STRINGS:" : "OTHER:") << std::endl
;
825 while( !eqcs2_i
.isFinished() ){
826 Node eqc
= (*eqcs2_i
);
827 bool print
= (t
==0 && eqc
.getType().isString() ) || (t
==1 && !eqc
.getType().isString() );
829 eq::EqClassIterator eqc2_i
= eq::EqClassIterator( eqc
, &d_equalityEngine
);
830 Trace("strings-eqc") << "Eqc( " << eqc
<< " ) : { ";
831 while( !eqc2_i
.isFinished() ) {
832 if( (*eqc2_i
)!=eqc
&& (*eqc2_i
).getKind()!=kind::EQUAL
){
833 Trace("strings-eqc") << (*eqc2_i
) << " ";
837 Trace("strings-eqc") << " } " << std::endl
;
838 EqcInfo
* ei
= getOrMakeEqcInfo( eqc
, false );
840 Trace("strings-eqc-debug") << "* Length term : " << ei
->d_length_term
.get() << std::endl
;
841 Trace("strings-eqc-debug") << "* Cardinality lemma k : " << ei
->d_cardinality_lem_k
.get() << std::endl
;
842 Trace("strings-eqc-debug") << "* Normalization length lemma : " << ei
->d_normalized_length
.get() << std::endl
;
847 Trace("strings-eqc") << std::endl
;
849 Trace("strings-eqc") << std::endl
;
851 unsigned sbegin
= itsr
->second
.first
;
852 unsigned send
= itsr
->second
.second
;
853 bool addedLemma
= false;
856 runStrategy(sbegin
, send
);
858 addedFact
= !d_pending
.empty();
859 addedLemma
= !d_lemma_cache
.empty();
862 // repeat if we did not add a lemma or conflict
863 }while( !d_conflict
&& !addedLemma
&& addedFact
);
865 Trace("strings-check") << "Theory of strings done full effort check " << addedLemma
<< " " << d_conflict
<< std::endl
;
867 Trace("strings-check") << "Theory of strings, done check : " << e
<< std::endl
;
868 Assert( d_pending
.empty() );
869 Assert( d_lemma_cache
.empty() );
872 bool TheoryStrings::needsCheckLastEffort() {
873 if( options::stringGuessModel() ){
874 return d_has_extf
.get();
880 void TheoryStrings::checkExtfReductions( int effort
) {
882 //std::vector< Node > nred;
883 //getExtTheory()->doReductions( effort, nred, false );
885 std::vector
< Node
> extf
= getExtTheory()->getActive();
886 Trace("strings-process") << " checking " << extf
.size() << " active extf"
888 for( unsigned i
=0; i
<extf
.size(); i
++ ){
890 Trace("strings-process") << " check " << n
<< ", active in model="
891 << d_extf_info_tmp
[n
].d_model_active
<< std::endl
;
893 int ret
= getReduction( effort
, n
, nr
);
894 Assert( nr
.isNull() );
896 getExtTheory()->markReduced( extf
[i
] );
905 TheoryStrings::EqcInfo::EqcInfo(context::Context
* c
)
908 d_cardinality_lem_k(c
),
909 d_normalized_length(c
)
913 TheoryStrings::EqcInfo
* TheoryStrings::getOrMakeEqcInfo( Node eqc
, bool doMake
) {
914 std::map
< Node
, EqcInfo
* >::iterator eqc_i
= d_eqc_info
.find( eqc
);
915 if( eqc_i
==d_eqc_info
.end() ){
917 EqcInfo
* ei
= new EqcInfo( getSatContext() );
918 d_eqc_info
[eqc
] = ei
;
924 return (*eqc_i
).second
;
929 /** Conflict when merging two constants */
930 void TheoryStrings::conflict(TNode a
, TNode b
){
932 Debug("strings-conflict") << "Making conflict..." << std::endl
;
935 conflictNode
= explain( a
.eqNode(b
) );
936 Trace("strings-conflict") << "CONFLICT: Eq engine conflict : " << conflictNode
<< std::endl
;
937 d_out
->conflict( conflictNode
);
941 /** called when a new equivalance class is created */
942 void TheoryStrings::eqNotifyNewClass(TNode t
){
943 Kind k
= t
.getKind();
944 if (k
== kind::STRING_LENGTH
|| k
== kind::STRING_CODE
)
946 Trace("strings-debug") << "New length eqc : " << t
<< std::endl
;
947 Node r
= d_equalityEngine
.getRepresentative(t
[0]);
948 EqcInfo
* ei
= getOrMakeEqcInfo( r
, true );
949 if (k
== kind::STRING_LENGTH
)
951 ei
->d_length_term
= t
[0];
955 ei
->d_code_term
= t
[0];
957 //we care about the length of this string
958 registerTerm( t
[0], 1 );
960 //getExtTheory()->registerTerm( t );
964 /** called when two equivalance classes will merge */
965 void TheoryStrings::eqNotifyPreMerge(TNode t1
, TNode t2
){
966 EqcInfo
* e2
= getOrMakeEqcInfo(t2
, false);
968 EqcInfo
* e1
= getOrMakeEqcInfo( t1
);
969 //add information from e2 to e1
970 if( !e2
->d_length_term
.get().isNull() ){
971 e1
->d_length_term
.set( e2
->d_length_term
);
973 if (!e2
->d_code_term
.get().isNull())
975 e1
->d_code_term
.set(e2
->d_code_term
);
977 if( e2
->d_cardinality_lem_k
.get()>e1
->d_cardinality_lem_k
.get() ) {
978 e1
->d_cardinality_lem_k
.set( e2
->d_cardinality_lem_k
);
980 if( !e2
->d_normalized_length
.get().isNull() ){
981 e1
->d_normalized_length
.set( e2
->d_normalized_length
);
986 /** called when two equivalance classes have merged */
987 void TheoryStrings::eqNotifyPostMerge(TNode t1
, TNode t2
) {
991 /** called when two equivalance classes are disequal */
992 void TheoryStrings::eqNotifyDisequal(TNode t1
, TNode t2
, TNode reason
) {
993 if( t1
.getType().isString() ){
994 //store disequalities between strings, may need to check if their lengths are equal/disequal
995 d_ee_disequalities
.push_back( t1
.eqNode( t2
) );
999 void TheoryStrings::addCarePairs( quantifiers::TermArgTrie
* t1
, quantifiers::TermArgTrie
* t2
, unsigned arity
, unsigned depth
) {
1002 Node f1
= t1
->getNodeData();
1003 Node f2
= t2
->getNodeData();
1004 if( !d_equalityEngine
.areEqual( f1
, f2
) ){
1005 Trace("strings-cg-debug") << "TheoryStrings::computeCareGraph(): checking function " << f1
<< " and " << f2
<< std::endl
;
1006 vector
< pair
<TNode
, TNode
> > currentPairs
;
1007 for (unsigned k
= 0; k
< f1
.getNumChildren(); ++ k
) {
1010 Assert( d_equalityEngine
.hasTerm(x
) );
1011 Assert( d_equalityEngine
.hasTerm(y
) );
1012 Assert( !d_equalityEngine
.areDisequal( x
, y
, false ) );
1013 Assert( !areCareDisequal( x
, y
) );
1014 if( !d_equalityEngine
.areEqual( x
, y
) ){
1015 if( d_equalityEngine
.isTriggerTerm(x
, THEORY_STRINGS
) && d_equalityEngine
.isTriggerTerm(y
, THEORY_STRINGS
) ){
1016 TNode x_shared
= d_equalityEngine
.getTriggerTermRepresentative(x
, THEORY_STRINGS
);
1017 TNode y_shared
= d_equalityEngine
.getTriggerTermRepresentative(y
, THEORY_STRINGS
);
1018 currentPairs
.push_back(make_pair(x_shared
, y_shared
));
1022 for (unsigned c
= 0; c
< currentPairs
.size(); ++ c
) {
1023 Trace("strings-cg-pair") << "TheoryStrings::computeCareGraph(): pair : " << currentPairs
[c
].first
<< " " << currentPairs
[c
].second
<< std::endl
;
1024 addCarePair(currentPairs
[c
].first
, currentPairs
[c
].second
);
1030 if( depth
<(arity
-1) ){
1031 //add care pairs internal to each child
1032 for( std::map
< TNode
, quantifiers::TermArgTrie
>::iterator it
= t1
->d_data
.begin(); it
!= t1
->d_data
.end(); ++it
){
1033 addCarePairs( &it
->second
, NULL
, arity
, depth
+1 );
1036 //add care pairs based on each pair of non-disequal arguments
1037 for( std::map
< TNode
, quantifiers::TermArgTrie
>::iterator it
= t1
->d_data
.begin(); it
!= t1
->d_data
.end(); ++it
){
1038 std::map
< TNode
, quantifiers::TermArgTrie
>::iterator it2
= it
;
1040 for( ; it2
!= t1
->d_data
.end(); ++it2
){
1041 if( !d_equalityEngine
.areDisequal(it
->first
, it2
->first
, false) ){
1042 if( !areCareDisequal(it
->first
, it2
->first
) ){
1043 addCarePairs( &it
->second
, &it2
->second
, arity
, depth
+1 );
1049 //add care pairs based on product of indices, non-disequal arguments
1050 for( std::map
< TNode
, quantifiers::TermArgTrie
>::iterator it
= t1
->d_data
.begin(); it
!= t1
->d_data
.end(); ++it
){
1051 for( std::map
< TNode
, quantifiers::TermArgTrie
>::iterator it2
= t2
->d_data
.begin(); it2
!= t2
->d_data
.end(); ++it2
){
1052 if( !d_equalityEngine
.areDisequal(it
->first
, it2
->first
, false) ){
1053 if( !areCareDisequal(it
->first
, it2
->first
) ){
1054 addCarePairs( &it
->second
, &it2
->second
, arity
, depth
+1 );
1063 void TheoryStrings::computeCareGraph(){
1064 //computing the care graph here is probably still necessary, due to operators that take non-string arguments TODO: verify
1065 Trace("strings-cg") << "TheoryStrings::computeCareGraph(): Build term indices..." << std::endl
;
1066 std::map
< Node
, quantifiers::TermArgTrie
> index
;
1067 std::map
< Node
, unsigned > arity
;
1068 unsigned functionTerms
= d_functionsTerms
.size();
1069 for (unsigned i
= 0; i
< functionTerms
; ++ i
) {
1070 TNode f1
= d_functionsTerms
[i
];
1071 Trace("strings-cg") << "...build for " << f1
<< std::endl
;
1072 Node op
= f1
.getOperator();
1073 std::vector
< TNode
> reps
;
1074 bool has_trigger_arg
= false;
1075 for( unsigned j
=0; j
<f1
.getNumChildren(); j
++ ){
1076 reps
.push_back( d_equalityEngine
.getRepresentative( f1
[j
] ) );
1077 if( d_equalityEngine
.isTriggerTerm( f1
[j
], THEORY_STRINGS
) ){
1078 has_trigger_arg
= true;
1081 if( has_trigger_arg
){
1082 index
[op
].addTerm( f1
, reps
);
1083 arity
[op
] = reps
.size();
1087 for( std::map
< Node
, quantifiers::TermArgTrie
>::iterator itii
= index
.begin(); itii
!= index
.end(); ++itii
){
1088 Trace("strings-cg") << "TheoryStrings::computeCareGraph(): Process index " << itii
->first
<< "..." << std::endl
;
1089 addCarePairs( &itii
->second
, NULL
, arity
[ itii
->first
], 0 );
1093 void TheoryStrings::assertPendingFact(Node atom
, bool polarity
, Node exp
) {
1094 Trace("strings-pending") << "Assert pending fact : " << atom
<< " " << polarity
<< " from " << exp
<< std::endl
;
1095 Assert(atom
.getKind() != kind::OR
, "Infer error: a split.");
1096 if( atom
.getKind()==kind::EQUAL
){
1097 Trace("strings-pending-debug") << " Register term" << std::endl
;
1098 for( unsigned j
=0; j
<2; j
++ ) {
1099 if( !d_equalityEngine
.hasTerm( atom
[j
] ) && atom
[j
].getType().isString() ) {
1100 registerTerm( atom
[j
], 0 );
1103 Trace("strings-pending-debug") << " Now assert equality" << std::endl
;
1104 d_equalityEngine
.assertEquality( atom
, polarity
, exp
);
1105 Trace("strings-pending-debug") << " Finished assert equality" << std::endl
;
1107 d_equalityEngine
.assertPredicate( atom
, polarity
, exp
);
1109 if( atom
.getKind()==kind::STRING_IN_REGEXP
){
1110 if( polarity
&& atom
[1].getKind()==kind::REGEXP_RANGE
){
1111 if( d_extf_infer_cache_u
.find( atom
)==d_extf_infer_cache_u
.end() ){
1112 d_extf_infer_cache_u
.insert( atom
);
1113 //length of first argument is one
1114 Node conc
= d_one
.eqNode( NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, atom
[0] ) );
1115 Node lem
= NodeManager::currentNM()->mkNode( kind::OR
, atom
.negate(), conc
);
1116 Trace("strings-lemma") << "Strings::Lemma RE-Range-Len : " << lem
<< std::endl
;
1117 d_out
->lemma( lem
);
1121 //register the atom here, since it may not create a new equivalence class
1122 //getExtTheory()->registerTerm( atom );
1124 Trace("strings-pending-debug") << " Now collect terms" << std::endl
;
1125 //collect extended function terms in the atom
1126 getExtTheory()->registerTermRec( atom
);
1127 Trace("strings-pending-debug") << " Finished collect terms" << std::endl
;
1130 void TheoryStrings::doPendingFacts() {
1132 while( !d_conflict
&& i
<d_pending
.size() ) {
1133 Node fact
= d_pending
[i
];
1134 Node exp
= d_pending_exp
[ fact
];
1135 if(fact
.getKind() == kind::AND
) {
1136 for(size_t j
=0; j
<fact
.getNumChildren(); j
++) {
1137 bool polarity
= fact
[j
].getKind() != kind::NOT
;
1138 TNode atom
= polarity
? fact
[j
] : fact
[j
][0];
1139 assertPendingFact(atom
, polarity
, exp
);
1142 bool polarity
= fact
.getKind() != kind::NOT
;
1143 TNode atom
= polarity
? fact
: fact
[0];
1144 assertPendingFact(atom
, polarity
, exp
);
1149 d_pending_exp
.clear();
1152 void TheoryStrings::doPendingLemmas() {
1153 if( !d_conflict
&& !d_lemma_cache
.empty() ){
1154 for( unsigned i
=0; i
<d_lemma_cache
.size(); i
++ ){
1155 Trace("strings-pending") << "Process pending lemma : " << d_lemma_cache
[i
] << std::endl
;
1156 d_out
->lemma( d_lemma_cache
[i
] );
1158 for( std::map
< Node
, bool >::iterator it
= d_pending_req_phase
.begin(); it
!= d_pending_req_phase
.end(); ++it
){
1159 Trace("strings-pending") << "Require phase : " << it
->first
<< ", polarity = " << it
->second
<< std::endl
;
1160 d_out
->requirePhase( it
->first
, it
->second
);
1163 d_lemma_cache
.clear();
1164 d_pending_req_phase
.clear();
1167 bool TheoryStrings::hasProcessed() {
1168 return d_conflict
|| !d_lemma_cache
.empty() || !d_pending
.empty();
1171 void TheoryStrings::addToExplanation( Node a
, Node b
, std::vector
< Node
>& exp
) {
1173 Debug("strings-explain") << "Add to explanation : " << a
<< " == " << b
<< std::endl
;
1174 Assert( areEqual( a
, b
) );
1175 exp
.push_back( a
.eqNode( b
) );
1179 void TheoryStrings::addToExplanation( Node lit
, std::vector
< Node
>& exp
) {
1180 if( !lit
.isNull() ){
1181 exp
.push_back( lit
);
1185 void TheoryStrings::checkInit() {
1187 d_eqc_to_const
.clear();
1188 d_eqc_to_const_base
.clear();
1189 d_eqc_to_const_exp
.clear();
1190 d_eqc_to_len_term
.clear();
1191 d_term_index
.clear();
1192 d_strings_eqc
.clear();
1194 std::map
< Kind
, unsigned > ncongruent
;
1195 std::map
< Kind
, unsigned > congruent
;
1196 d_emptyString_r
= getRepresentative( d_emptyString
);
1197 eq::EqClassesIterator eqcs_i
= eq::EqClassesIterator( &d_equalityEngine
);
1198 while( !eqcs_i
.isFinished() ){
1199 Node eqc
= (*eqcs_i
);
1200 TypeNode tn
= eqc
.getType();
1201 if( !tn
.isRegExp() ){
1202 if( tn
.isString() ){
1203 d_strings_eqc
.push_back( eqc
);
1206 eq::EqClassIterator eqc_i
= eq::EqClassIterator( eqc
, &d_equalityEngine
);
1207 while( !eqc_i
.isFinished() ) {
1210 d_eqc_to_const
[eqc
] = n
;
1211 d_eqc_to_const_base
[eqc
] = n
;
1212 d_eqc_to_const_exp
[eqc
] = Node::null();
1213 }else if( tn
.isInteger() ){
1214 if( n
.getKind()==kind::STRING_LENGTH
){
1215 Node nr
= getRepresentative( n
[0] );
1216 d_eqc_to_len_term
[nr
] = n
[0];
1218 }else if( n
.getNumChildren()>0 ){
1219 Kind k
= n
.getKind();
1220 if( k
!=kind::EQUAL
){
1221 if( d_congruent
.find( n
)==d_congruent
.end() ){
1222 std::vector
< Node
> c
;
1223 Node nc
= d_term_index
[k
].add( n
, 0, this, d_emptyString_r
, c
);
1225 //check if we have inferred a new equality by removal of empty components
1226 if( n
.getKind()==kind::STRING_CONCAT
&& !areEqual( nc
, n
) ){
1227 std::vector
< Node
> exp
;
1228 unsigned count
[2] = { 0, 0 };
1229 while( count
[0]<nc
.getNumChildren() || count
[1]<n
.getNumChildren() ){
1230 //explain empty prefixes
1231 for( unsigned t
=0; t
<2; t
++ ){
1232 Node nn
= t
==0 ? nc
: n
;
1233 while( count
[t
]<nn
.getNumChildren() &&
1234 ( nn
[count
[t
]]==d_emptyString
|| areEqual( nn
[count
[t
]], d_emptyString
) ) ){
1235 if( nn
[count
[t
]]!=d_emptyString
){
1236 exp
.push_back( nn
[count
[t
]].eqNode( d_emptyString
) );
1241 //explain equal components
1242 if( count
[0]<nc
.getNumChildren() ){
1243 Assert( count
[1]<n
.getNumChildren() );
1244 if( nc
[count
[0]]!=n
[count
[1]] ){
1245 exp
.push_back( nc
[count
[0]].eqNode( n
[count
[1]] ) );
1251 //infer the equality
1252 sendInference( exp
, n
.eqNode( nc
), "I_Norm" );
1253 }else if( getExtTheory()->hasFunctionKind( n
.getKind() ) ){
1254 //mark as congruent : only process if neither has been reduced
1255 getExtTheory()->markCongruent( nc
, n
);
1257 //this node is congruent to another one, we can ignore it
1258 Trace("strings-process-debug") << " congruent term : " << n
<< std::endl
;
1259 d_congruent
.insert( n
);
1261 }else if( k
==kind::STRING_CONCAT
&& c
.size()==1 ){
1262 Trace("strings-process-debug") << " congruent term by singular : " << n
<< " " << c
[0] << std::endl
;
1264 if( !areEqual( c
[0], n
) ){
1265 std::vector
< Node
> exp
;
1266 //explain empty components
1267 bool foundNEmpty
= false;
1268 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ){
1269 if( areEqual( n
[i
], d_emptyString
) ){
1270 if( n
[i
]!=d_emptyString
){
1271 exp
.push_back( n
[i
].eqNode( d_emptyString
) );
1274 Assert( !foundNEmpty
);
1276 exp
.push_back( n
[i
].eqNode( c
[0] ) );
1281 AlwaysAssert( foundNEmpty
);
1282 //infer the equality
1283 sendInference( exp
, n
.eqNode( c
[0] ), "I_Norm_S" );
1285 d_congruent
.insert( n
);
1295 if( d_congruent
.find( n
)==d_congruent
.end() ){
1299 Trace("strings-process-debug") << " congruent variable : " << n
<< std::endl
;
1300 d_congruent
.insert( n
);
1309 if( Trace
.isOn("strings-process") ){
1310 for( std::map
< Kind
, TermIndex
>::iterator it
= d_term_index
.begin(); it
!= d_term_index
.end(); ++it
){
1311 Trace("strings-process") << " Terms[" << it
->first
<< "] = " << ncongruent
[it
->first
] << "/" << (congruent
[it
->first
]+ncongruent
[it
->first
]) << std::endl
;
1316 void TheoryStrings::checkConstantEquivalenceClasses()
1320 std::vector
<Node
> vecc
;
1324 Trace("strings-process-debug") << "Check constant equivalence classes..."
1326 prevSize
= d_eqc_to_const
.size();
1327 checkConstantEquivalenceClasses(&d_term_index
[kind::STRING_CONCAT
], vecc
);
1328 } while (!hasProcessed() && d_eqc_to_const
.size() > prevSize
);
1331 void TheoryStrings::checkConstantEquivalenceClasses( TermIndex
* ti
, std::vector
< Node
>& vecc
) {
1332 Node n
= ti
->d_data
;
1334 //construct the constant
1335 Node c
= mkConcat( vecc
);
1336 if( !areEqual( n
, c
) ){
1337 Trace("strings-debug") << "Constant eqc : " << c
<< " for " << n
<< std::endl
;
1338 Trace("strings-debug") << " ";
1339 for( unsigned i
=0; i
<vecc
.size(); i
++ ){
1340 Trace("strings-debug") << vecc
[i
] << " ";
1342 Trace("strings-debug") << std::endl
;
1344 unsigned countc
= 0;
1345 std::vector
< Node
> exp
;
1346 while( count
<n
.getNumChildren() ){
1347 while( count
<n
.getNumChildren() && areEqual( n
[count
], d_emptyString
) ){
1348 addToExplanation( n
[count
], d_emptyString
, exp
);
1351 if( count
<n
.getNumChildren() ){
1352 Trace("strings-debug") << "...explain " << n
[count
] << " " << vecc
[countc
] << std::endl
;
1353 if( !areEqual( n
[count
], vecc
[countc
] ) ){
1354 Node nrr
= getRepresentative( n
[count
] );
1355 Assert( !d_eqc_to_const_exp
[nrr
].isNull() );
1356 addToExplanation( n
[count
], d_eqc_to_const_base
[nrr
], exp
);
1357 exp
.push_back( d_eqc_to_const_exp
[nrr
] );
1359 addToExplanation( n
[count
], vecc
[countc
], exp
);
1365 //exp contains an explanation of n==c
1366 Assert( countc
==vecc
.size() );
1368 sendInference( exp
, n
.eqNode( c
), "I_CONST_MERGE" );
1370 }else if( !hasProcessed() ){
1371 Node nr
= getRepresentative( n
);
1372 std::map
< Node
, Node
>::iterator it
= d_eqc_to_const
.find( nr
);
1373 if( it
==d_eqc_to_const
.end() ){
1374 Trace("strings-debug") << "Set eqc const " << n
<< " to " << c
<< std::endl
;
1375 d_eqc_to_const
[nr
] = c
;
1376 d_eqc_to_const_base
[nr
] = n
;
1377 d_eqc_to_const_exp
[nr
] = mkAnd( exp
);
1378 }else if( c
!=it
->second
){
1380 Trace("strings-debug") << "Conflict, other constant was " << it
->second
<< ", this constant was " << c
<< std::endl
;
1381 if( d_eqc_to_const_exp
[nr
].isNull() ){
1382 // n==c ^ n == c' => false
1383 addToExplanation( n
, it
->second
, exp
);
1385 // n==c ^ n == d_eqc_to_const_base[nr] == c' => false
1386 exp
.push_back( d_eqc_to_const_exp
[nr
] );
1387 addToExplanation( n
, d_eqc_to_const_base
[nr
], exp
);
1389 sendInference( exp
, d_false
, "I_CONST_CONFLICT" );
1392 Trace("strings-debug") << "Duplicate constant." << std::endl
;
1397 for( std::map
< TNode
, TermIndex
>::iterator it
= ti
->d_children
.begin(); it
!= ti
->d_children
.end(); ++it
){
1398 std::map
< Node
, Node
>::iterator itc
= d_eqc_to_const
.find( it
->first
);
1399 if( itc
!=d_eqc_to_const
.end() ){
1400 vecc
.push_back( itc
->second
);
1401 checkConstantEquivalenceClasses( &it
->second
, vecc
);
1403 if( hasProcessed() ){
1410 void TheoryStrings::checkExtfEval( int effort
) {
1411 Trace("strings-extf-list") << "Active extended functions, effort=" << effort
<< " : " << std::endl
;
1412 d_extf_info_tmp
.clear();
1413 bool has_nreduce
= false;
1414 std::vector
< Node
> terms
= getExtTheory()->getActive();
1415 std::vector
< Node
> sterms
;
1416 std::vector
< std::vector
< Node
> > exp
;
1417 getExtTheory()->getSubstitutedTerms( effort
, terms
, sterms
, exp
);
1418 for( unsigned i
=0; i
<terms
.size(); i
++ ){
1420 Node sn
= sterms
[i
];
1421 //setup information about extf
1422 d_extf_info_tmp
[n
].init();
1423 std::map
< Node
, ExtfInfoTmp
>::iterator itit
= d_extf_info_tmp
.find( n
);
1424 if( n
.getType().isBoolean() ){
1425 if( areEqual( n
, d_true
) ){
1426 itit
->second
.d_pol
= 1;
1427 }else if( areEqual( n
, d_false
) ){
1428 itit
->second
.d_pol
= -1;
1431 Trace("strings-extf-debug") << "Check extf " << n
<< " == " << sn
<< ", pol = " << itit
->second
.d_pol
<< ", effort=" << effort
<< "..." << std::endl
;
1435 itit
->second
.d_exp
.insert( itit
->second
.d_exp
.end(), exp
[i
].begin(), exp
[i
].end() );
1436 // inference is rewriting the substituted node
1437 Node nrc
= Rewriter::rewrite( sn
);
1438 //if rewrites to a constant, then do the inference and mark as reduced
1439 if( nrc
.isConst() ){
1441 getExtTheory()->markReduced( n
);
1442 Trace("strings-extf-debug") << " resolvable by evaluation..." << std::endl
;
1443 std::vector
< Node
> exps
;
1444 // The following optimization gets the "symbolic definition" of
1445 // an extended term. The symbolic definition of a term t is a term
1446 // t' where constants are replaced by their corresponding proxy
1448 // For example, if lsym is a proxy variable for "", then
1449 // str.replace( lsym, lsym, lsym ) is the symbolic definition for
1450 // str.replace( "", "", "" ). It is generally better to use symbolic
1451 // definitions when doing cd-rewriting for the purpose of minimizing
1452 // clauses, e.g. we infer the unit equality:
1453 // str.replace( lsym, lsym, lsym ) == ""
1454 // instead of making this inference multiple times:
1455 // x = "" => str.replace( x, x, x ) == ""
1456 // y = "" => str.replace( y, y, y ) == ""
1457 Trace("strings-extf-debug") << " get symbolic definition..." << std::endl
;
1458 Node nrs
= getSymbolicDefinition( sn
, exps
);
1459 if( !nrs
.isNull() ){
1460 Trace("strings-extf-debug") << " rewrite " << nrs
<< "..." << std::endl
;
1461 Node nrsr
= Rewriter::rewrite(nrs
);
1462 // ensure the symbolic form is not rewritable
1465 // we cannot use the symbolic definition if it rewrites
1466 Trace("strings-extf-debug") << " symbolic definition is trivial..." << std::endl
;
1470 Trace("strings-extf-debug") << " could not infer symbolic definition." << std::endl
;
1473 if( !nrs
.isNull() ){
1474 Trace("strings-extf-debug") << " symbolic def : " << nrs
<< std::endl
;
1475 if( !areEqual( nrs
, nrc
) ){
1476 //infer symbolic unit
1477 if( n
.getType().isBoolean() ){
1478 conc
= nrc
==d_true
? nrs
: nrs
.negate();
1480 conc
= nrs
.eqNode( nrc
);
1482 itit
->second
.d_exp
.clear();
1485 if( !areEqual( n
, nrc
) ){
1486 if( n
.getType().isBoolean() ){
1487 if( areEqual( n
, nrc
==d_true
? d_false
: d_true
) ){
1488 itit
->second
.d_exp
.push_back( nrc
==d_true
? n
.negate() : n
);
1491 conc
= nrc
==d_true
? n
: n
.negate();
1494 conc
= n
.eqNode( nrc
);
1498 if( !conc
.isNull() ){
1499 Trace("strings-extf") << " resolve extf : " << sn
<< " -> " << nrc
<< std::endl
;
1500 sendInference( itit
->second
.d_exp
, conc
, effort
==0 ? "EXTF" : "EXTF-N", true );
1502 Trace("strings-extf-debug") << " conflict, return." << std::endl
;
1507 //check if it is already equal, if so, mark as reduced. Otherwise, do nothing.
1508 if( areEqual( n
, nrc
) ){
1509 Trace("strings-extf") << " resolved extf, since satisfied by model: " << n
<< std::endl
;
1510 itit
->second
.d_model_active
= false;
1513 //if it reduces to a conjunction, infer each and reduce
1514 }else if( ( nrc
.getKind()==kind::OR
&& itit
->second
.d_pol
==-1 ) || ( nrc
.getKind()==kind::AND
&& itit
->second
.d_pol
==1 ) ){
1516 getExtTheory()->markReduced( n
);
1517 itit
->second
.d_exp
.push_back( itit
->second
.d_pol
==-1 ? n
.negate() : n
);
1518 Trace("strings-extf-debug") << " decomposable..." << std::endl
;
1519 Trace("strings-extf") << " resolve extf : " << sn
<< " -> " << nrc
<< ", pol = " << itit
->second
.d_pol
<< std::endl
;
1520 for( unsigned i
=0; i
<nrc
.getNumChildren(); i
++ ){
1521 sendInference( itit
->second
.d_exp
, itit
->second
.d_pol
==-1 ? nrc
[i
].negate() : nrc
[i
], effort
==0 ? "EXTF_d" : "EXTF_d-N" );
1527 to_reduce
= sterms
[i
];
1530 if( !to_reduce
.isNull() ){
1533 Trace("strings-extf") << " cannot rewrite extf : " << to_reduce
<< std::endl
;
1535 checkExtfInference( n
, to_reduce
, itit
->second
, effort
);
1536 if( Trace
.isOn("strings-extf-list") ){
1537 Trace("strings-extf-list") << " * " << to_reduce
;
1538 if( itit
->second
.d_pol
!=0 ){
1539 Trace("strings-extf-list") << ", pol = " << itit
->second
.d_pol
;
1542 Trace("strings-extf-list") << ", from " << n
;
1544 Trace("strings-extf-list") << std::endl
;
1546 if( getExtTheory()->isActive( n
) && itit
->second
.d_model_active
){
1551 d_has_extf
= has_nreduce
;
1554 void TheoryStrings::checkExtfInference( Node n
, Node nr
, ExtfInfoTmp
& in
, int effort
){
1555 //make additional inferences that do not contribute to the reduction of n, but may help show a refutation
1557 //add original to explanation
1558 in
.d_exp
.push_back( in
.d_pol
==1 ? n
: n
.negate() );
1560 //d_extf_infer_cache stores whether we have made the inferences associated with a node n,
1561 // this may need to be generalized if multiple inferences apply
1563 if( nr
.getKind()==kind::STRING_STRCTN
){
1564 if( ( in
.d_pol
==1 && nr
[1].getKind()==kind::STRING_CONCAT
) || ( in
.d_pol
==-1 && nr
[0].getKind()==kind::STRING_CONCAT
) ){
1565 if( d_extf_infer_cache
.find( nr
)==d_extf_infer_cache
.end() ){
1566 d_extf_infer_cache
.insert( nr
);
1568 //one argument does (not) contain each of the components of the other argument
1569 int index
= in
.d_pol
==1 ? 1 : 0;
1570 std::vector
< Node
> children
;
1571 children
.push_back( nr
[0] );
1572 children
.push_back( nr
[1] );
1573 //Node exp_n = mkAnd( exp );
1574 for( unsigned i
=0; i
<nr
[index
].getNumChildren(); i
++ ){
1575 children
[index
] = nr
[index
][i
];
1576 Node conc
= NodeManager::currentNM()->mkNode( kind::STRING_STRCTN
, children
);
1577 conc
= Rewriter::rewrite(in
.d_pol
== 1 ? conc
: conc
.negate());
1578 // check if it already (does not) hold
1581 if (areEqual(conc
, d_false
))
1583 // should be a conflict
1584 sendInference(in
.d_exp
, conc
, "CTN_Decompose");
1586 else if (getExtTheory()->hasFunctionKind(conc
.getKind()))
1588 // can mark as reduced, since model for n => model for conc
1589 getExtTheory()->markReduced(conc
);
1596 //store this (reduced) assertion
1597 //Assert( effort==0 || nr[0]==getRepresentative( nr[0] ) );
1598 bool pol
= in
.d_pol
==1;
1599 if( std::find( d_extf_info_tmp
[nr
[0]].d_ctn
[pol
].begin(), d_extf_info_tmp
[nr
[0]].d_ctn
[pol
].end(), nr
[1] )==d_extf_info_tmp
[nr
[0]].d_ctn
[pol
].end() ){
1600 Trace("strings-extf-debug") << " store contains info : " << nr
[0] << " " << pol
<< " " << nr
[1] << std::endl
;
1601 d_extf_info_tmp
[nr
[0]].d_ctn
[pol
].push_back( nr
[1] );
1602 d_extf_info_tmp
[nr
[0]].d_ctn_from
[pol
].push_back( n
);
1603 //transitive closure for contains
1605 for( unsigned i
=0; i
<d_extf_info_tmp
[nr
[0]].d_ctn
[opol
].size(); i
++ ){
1606 Node onr
= d_extf_info_tmp
[nr
[0]].d_ctn
[opol
][i
];
1607 Node conc
= NodeManager::currentNM()->mkNode( kind::STRING_STRCTN
, pol
? nr
[1] : onr
, pol
? onr
: nr
[1] );
1608 conc
= Rewriter::rewrite( conc
);
1609 bool do_infer
= false;
1610 if( conc
.getKind()==kind::EQUAL
){
1611 do_infer
= !areDisequal( conc
[0], conc
[1] );
1613 do_infer
= !areEqual( conc
, d_false
);
1616 conc
= conc
.negate();
1617 std::vector
< Node
> exp_c
;
1618 exp_c
.insert( exp_c
.end(), in
.d_exp
.begin(), in
.d_exp
.end() );
1619 Node ofrom
= d_extf_info_tmp
[nr
[0]].d_ctn_from
[opol
][i
];
1620 Assert( d_extf_info_tmp
.find( ofrom
)!=d_extf_info_tmp
.end() );
1621 exp_c
.insert( exp_c
.end(), d_extf_info_tmp
[ofrom
].d_exp
.begin(), d_extf_info_tmp
[ofrom
].d_exp
.end() );
1622 sendInference( exp_c
, conc
, "CTN_Trans" );
1626 Trace("strings-extf-debug") << " redundant." << std::endl
;
1627 getExtTheory()->markReduced( n
);
1634 Node
TheoryStrings::getSymbolicDefinition( Node n
, std::vector
< Node
>& exp
) {
1635 if( n
.getNumChildren()==0 ){
1636 NodeNodeMap::const_iterator it
= d_proxy_var
.find( n
);
1637 if( it
==d_proxy_var
.end() ){
1638 return Node::null();
1640 Node eq
= n
.eqNode( (*it
).second
);
1641 eq
= Rewriter::rewrite( eq
);
1642 if( std::find( exp
.begin(), exp
.end(), eq
)==exp
.end() ){
1643 exp
.push_back( eq
);
1645 return (*it
).second
;
1648 std::vector
< Node
> children
;
1649 if (n
.getMetaKind() == kind::metakind::PARAMETERIZED
) {
1650 children
.push_back( n
.getOperator() );
1652 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ){
1653 if( n
.getKind()==kind::STRING_IN_REGEXP
&& i
==1 ){
1654 children
.push_back( n
[i
] );
1656 Node ns
= getSymbolicDefinition( n
[i
], exp
);
1658 return Node::null();
1660 children
.push_back( ns
);
1664 return NodeManager::currentNM()->mkNode( n
.getKind(), children
);
1668 Node
TheoryStrings::getConstantEqc( Node eqc
) {
1669 std::map
< Node
, Node
>::iterator it
= d_eqc_to_const
.find( eqc
);
1670 if( it
!=d_eqc_to_const
.end() ){
1673 return Node::null();
1677 void TheoryStrings::debugPrintFlatForms( const char * tc
){
1678 for( unsigned k
=0; k
<d_strings_eqc
.size(); k
++ ){
1679 Node eqc
= d_strings_eqc
[k
];
1680 if( d_eqc
[eqc
].size()>1 ){
1681 Trace( tc
) << "EQC [" << eqc
<< "]" << std::endl
;
1683 Trace( tc
) << "eqc [" << eqc
<< "]";
1685 std::map
< Node
, Node
>::iterator itc
= d_eqc_to_const
.find( eqc
);
1686 if( itc
!=d_eqc_to_const
.end() ){
1687 Trace( tc
) << " C: " << itc
->second
;
1688 if( d_eqc
[eqc
].size()>1 ){
1689 Trace( tc
) << std::endl
;
1692 if( d_eqc
[eqc
].size()>1 ){
1693 for( unsigned i
=0; i
<d_eqc
[eqc
].size(); i
++ ){
1694 Node n
= d_eqc
[eqc
][i
];
1696 for( unsigned j
=0; j
<d_flat_form
[n
].size(); j
++ ){
1697 Node fc
= d_flat_form
[n
][j
];
1698 itc
= d_eqc_to_const
.find( fc
);
1700 if( itc
!=d_eqc_to_const
.end() ){
1701 Trace( tc
) << itc
->second
;
1707 Trace( tc
) << ", from " << n
;
1709 Trace( tc
) << std::endl
;
1712 Trace( tc
) << std::endl
;
1715 Trace( tc
) << std::endl
;
1718 void TheoryStrings::debugPrintNormalForms( const char * tc
) {
1721 struct sortConstLength
{
1722 std::map
< Node
, unsigned > d_const_length
;
1723 bool operator() (Node i
, Node j
) {
1724 std::map
< Node
, unsigned >::iterator it_i
= d_const_length
.find( i
);
1725 std::map
< Node
, unsigned >::iterator it_j
= d_const_length
.find( j
);
1726 if( it_i
==d_const_length
.end() ){
1727 if( it_j
==d_const_length
.end() ){
1733 if( it_j
==d_const_length
.end() ){
1736 return it_i
->second
<it_j
->second
;
1742 void TheoryStrings::checkCycles()
1744 // first check for cycles, while building ordering of equivalence classes
1745 d_flat_form
.clear();
1746 d_flat_form_index
.clear();
1748 //rebuild strings eqc based on acyclic ordering
1749 std::vector
< Node
> eqc
;
1750 eqc
.insert( eqc
.end(), d_strings_eqc
.begin(), d_strings_eqc
.end() );
1751 d_strings_eqc
.clear();
1752 if( options::stringBinaryCsp() ){
1753 //sort: process smallest constants first (necessary if doing binary splits)
1754 sortConstLength scl
;
1755 for( unsigned i
=0; i
<eqc
.size(); i
++ ){
1756 std::map
< Node
, Node
>::iterator itc
= d_eqc_to_const
.find( eqc
[i
] );
1757 if( itc
!=d_eqc_to_const
.end() ){
1758 scl
.d_const_length
[eqc
[i
]] = itc
->second
.getConst
<String
>().size();
1761 std::sort( eqc
.begin(), eqc
.end(), scl
);
1763 for( unsigned i
=0; i
<eqc
.size(); i
++ ){
1764 std::vector
< Node
> curr
;
1765 std::vector
< Node
> exp
;
1766 checkCycles( eqc
[i
], curr
, exp
);
1767 if( hasProcessed() ){
1773 void TheoryStrings::checkFlatForms()
1775 // debug print flat forms
1776 if (Trace
.isOn("strings-ff"))
1778 Trace("strings-ff") << "Flat forms : " << std::endl
;
1779 debugPrintFlatForms("strings-ff");
1782 // inferences without recursively expanding flat forms
1784 //(1) approximate equality by containment, infer conflicts
1785 for (const Node
& eqc
: d_strings_eqc
)
1787 Node c
= getConstantEqc(eqc
);
1790 // if equivalence class is constant, all component constants in flat forms
1791 // must be contained in it, in order
1792 std::map
<Node
, std::vector
<Node
> >::iterator it
= d_eqc
.find(eqc
);
1793 if (it
!= d_eqc
.end())
1795 for (const Node
& n
: it
->second
)
1798 if (!TheoryStringsRewriter::canConstantContainList(
1799 c
, d_flat_form
[n
], firstc
, lastc
))
1801 Trace("strings-ff-debug") << "Flat form for " << n
1802 << " cannot be contained in constant "
1804 Trace("strings-ff-debug") << " indices = " << firstc
<< "/"
1805 << lastc
<< std::endl
;
1806 // conflict, explanation is n = base ^ base = c ^ relevant portion
1808 std::vector
<Node
> exp
;
1809 Assert(d_eqc_to_const_base
.find(eqc
) != d_eqc_to_const_base
.end());
1810 addToExplanation(n
, d_eqc_to_const_base
[eqc
], exp
);
1811 Assert(d_eqc_to_const_exp
.find(eqc
) != d_eqc_to_const_exp
.end());
1812 if (!d_eqc_to_const_exp
[eqc
].isNull())
1814 exp
.push_back(d_eqc_to_const_exp
[eqc
]);
1816 for (int e
= firstc
; e
<= lastc
; e
++)
1818 if (d_flat_form
[n
][e
].isConst())
1820 Assert(e
>= 0 && e
< (int)d_flat_form_index
[n
].size());
1821 Assert(d_flat_form_index
[n
][e
] >= 0
1822 && d_flat_form_index
[n
][e
] < (int)n
.getNumChildren());
1824 d_flat_form
[n
][e
], n
[d_flat_form_index
[n
][e
]], exp
);
1827 Node conc
= d_false
;
1828 sendInference(exp
, conc
, "F_NCTN");
1836 //(2) scan lists, unification to infer conflicts and equalities
1837 for (const Node
& eqc
: d_strings_eqc
)
1839 std::map
<Node
, std::vector
<Node
> >::iterator it
= d_eqc
.find(eqc
);
1840 if (it
== d_eqc
.end() || it
->second
.size() <= 1)
1844 // iterate over start index
1845 for (unsigned start
= 0; start
< it
->second
.size() - 1; start
++)
1847 for (unsigned r
= 0; r
< 2; r
++)
1849 bool isRev
= r
== 1;
1850 checkFlatForm(it
->second
, start
, isRev
);
1860 void TheoryStrings::checkFlatForm(std::vector
<Node
>& eqc
,
1865 std::vector
<Node
> inelig
;
1866 for (unsigned i
= 0; i
<= start
; i
++)
1868 inelig
.push_back(eqc
[start
]);
1870 Node a
= eqc
[start
];
1874 std::vector
<Node
> exp
;
1877 unsigned eqc_size
= eqc
.size();
1878 unsigned asize
= d_flat_form
[a
].size();
1881 for (unsigned i
= start
+ 1; i
< eqc_size
; i
++)
1884 if (std::find(inelig
.begin(), inelig
.end(), b
) == inelig
.end())
1886 unsigned bsize
= d_flat_form
[b
].size();
1890 std::vector
<Node
> conc_c
;
1891 for (unsigned j
= count
; j
< bsize
; j
++)
1894 b
[d_flat_form_index
[b
][j
]].eqNode(d_emptyString
));
1896 Assert(!conc_c
.empty());
1897 conc
= mkAnd(conc_c
);
1900 // swap, will enforce is empty past current
1906 inelig
.push_back(eqc
[i
]);
1912 Node curr
= d_flat_form
[a
][count
];
1913 Node curr_c
= getConstantEqc(curr
);
1914 Node ac
= a
[d_flat_form_index
[a
][count
]];
1915 std::vector
<Node
> lexp
;
1916 Node lcurr
= getLength(ac
, lexp
);
1917 for (unsigned i
= 1; i
< eqc_size
; i
++)
1920 if (std::find(inelig
.begin(), inelig
.end(), b
) == inelig
.end())
1922 if (count
== d_flat_form
[b
].size())
1924 inelig
.push_back(b
);
1926 std::vector
<Node
> conc_c
;
1927 for (unsigned j
= count
; j
< asize
; j
++)
1930 a
[d_flat_form_index
[a
][j
]].eqNode(d_emptyString
));
1932 Assert(!conc_c
.empty());
1933 conc
= mkAnd(conc_c
);
1941 Node cc
= d_flat_form
[b
][count
];
1944 Node bc
= b
[d_flat_form_index
[b
][count
]];
1945 inelig
.push_back(b
);
1946 Assert(!areEqual(curr
, cc
));
1947 Node cc_c
= getConstantEqc(cc
);
1948 if (!curr_c
.isNull() && !cc_c
.isNull())
1950 // check for constant conflict
1952 Node s
= TheoryStringsRewriter::splitConstant(
1953 cc_c
, curr_c
, index
, isRev
);
1956 addToExplanation(ac
, d_eqc_to_const_base
[curr
], exp
);
1957 addToExplanation(d_eqc_to_const_exp
[curr
], exp
);
1958 addToExplanation(bc
, d_eqc_to_const_base
[cc
], exp
);
1959 addToExplanation(d_eqc_to_const_exp
[cc
], exp
);
1965 else if ((d_flat_form
[a
].size() - 1) == count
1966 && (d_flat_form
[b
].size() - 1) == count
)
1968 conc
= ac
.eqNode(bc
);
1974 // if lengths are the same, apply LengthEq
1975 std::vector
<Node
> lexp2
;
1976 Node lcc
= getLength(bc
, lexp2
);
1977 if (areEqual(lcurr
, lcc
))
1979 Trace("strings-ff-debug") << "Infer " << ac
<< " == " << bc
1980 << " since " << lcurr
1981 << " == " << lcc
<< std::endl
;
1982 // exp_n.push_back( getLength( curr, true ).eqNode(
1983 // getLength( cc, true ) ) );
1984 Trace("strings-ff-debug") << "Explanation for " << lcurr
1986 for (unsigned j
= 0; j
< lexp
.size(); j
++)
1988 Trace("strings-ff-debug") << lexp
[j
] << std::endl
;
1990 Trace("strings-ff-debug") << "Explanation for " << lcc
1992 for (unsigned j
= 0; j
< lexp2
.size(); j
++)
1994 Trace("strings-ff-debug") << lexp2
[j
] << std::endl
;
1996 exp
.insert(exp
.end(), lexp
.begin(), lexp
.end());
1997 exp
.insert(exp
.end(), lexp2
.begin(), lexp2
.end());
1998 addToExplanation(lcurr
, lcc
, exp
);
1999 conc
= ac
.eqNode(bc
);
2011 Trace("strings-ff-debug")
2012 << "Found inference : " << conc
<< " based on equality " << a
2013 << " == " << b
<< ", " << isRev
<< " " << inf_type
<< std::endl
;
2014 addToExplanation(a
, b
, exp
);
2015 // explain why prefixes up to now were the same
2016 for (unsigned j
= 0; j
< count
; j
++)
2018 Trace("strings-ff-debug") << "Add at " << d_flat_form_index
[a
][j
] << " "
2019 << d_flat_form_index
[b
][j
] << std::endl
;
2021 a
[d_flat_form_index
[a
][j
]], b
[d_flat_form_index
[b
][j
]], exp
);
2023 // explain why other components up to now are empty
2024 for (unsigned t
= 0; t
< 2; t
++)
2026 Node c
= t
== 0 ? a
: b
;
2028 if (inf_type
== 3 || (t
== 1 && inf_type
== 2))
2030 // explain all the empty components for F_EndpointEq, all for
2031 // the short end for F_EndpointEmp
2032 jj
= isRev
? -1 : c
.getNumChildren();
2036 jj
= t
== 0 ? d_flat_form_index
[a
][count
]
2037 : d_flat_form_index
[b
][count
];
2039 int startj
= isRev
? jj
+ 1 : 0;
2040 int endj
= isRev
? c
.getNumChildren() : jj
;
2041 for (int j
= startj
; j
< endj
; j
++)
2043 if (areEqual(c
[j
], d_emptyString
))
2045 addToExplanation(c
[j
], d_emptyString
, exp
);
2049 // notice that F_EndpointEmp is not typically applied, since
2050 // strict prefix equality ( a.b = a ) where a,b non-empty
2051 // is conflicting by arithmetic len(a.b)=len(a)+len(b)!=len(a)
2058 : (inf_type
== 1 ? "F_Unify" : (inf_type
== 2 ? "F_EndpointEmp"
2059 : "F_EndpointEq")));
2067 } while (inelig
.size() < eqc
.size());
2069 for (const Node
& n
: eqc
)
2071 std::reverse(d_flat_form
[n
].begin(), d_flat_form
[n
].end());
2072 std::reverse(d_flat_form_index
[n
].begin(), d_flat_form_index
[n
].end());
2076 Node
TheoryStrings::checkCycles( Node eqc
, std::vector
< Node
>& curr
, std::vector
< Node
>& exp
){
2077 if( std::find( curr
.begin(), curr
.end(), eqc
)!=curr
.end() ){
2080 }else if( std::find( d_strings_eqc
.begin(), d_strings_eqc
.end(), eqc
)==d_strings_eqc
.end() ){
2081 curr
.push_back( eqc
);
2082 //look at all terms in this equivalence class
2083 eq::EqClassIterator eqc_i
= eq::EqClassIterator( eqc
, &d_equalityEngine
);
2084 while( !eqc_i
.isFinished() ) {
2086 if( d_congruent
.find( n
)==d_congruent
.end() ){
2087 if( n
.getKind() == kind::STRING_CONCAT
){
2088 Trace("strings-cycle") << eqc
<< " check term : " << n
<< " in " << eqc
<< std::endl
;
2089 if( eqc
!=d_emptyString_r
){
2090 d_eqc
[eqc
].push_back( n
);
2092 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ){
2093 Node nr
= getRepresentative( n
[i
] );
2094 if( eqc
==d_emptyString_r
){
2095 //for empty eqc, ensure all components are empty
2096 if( nr
!=d_emptyString_r
){
2097 std::vector
< Node
> exp
;
2098 exp
.push_back( n
.eqNode( d_emptyString
) );
2099 sendInference( exp
, n
[i
].eqNode( d_emptyString
), "I_CYCLE_E" );
2100 return Node::null();
2103 if( nr
!=d_emptyString_r
){
2104 d_flat_form
[n
].push_back( nr
);
2105 d_flat_form_index
[n
].push_back( i
);
2107 //for non-empty eqc, recurse and see if we find a loop
2108 Node ncy
= checkCycles( nr
, curr
, exp
);
2109 if( !ncy
.isNull() ){
2110 Trace("strings-cycle") << eqc
<< " cycle: " << ncy
<< " at " << n
<< "[" << i
<< "] : " << n
[i
] << std::endl
;
2111 addToExplanation( n
, eqc
, exp
);
2112 addToExplanation( nr
, n
[i
], exp
);
2114 //can infer all other components must be empty
2115 for( unsigned j
=0; j
<n
.getNumChildren(); j
++ ){
2116 //take first non-empty
2117 if( j
!=i
&& !areEqual( n
[j
], d_emptyString
) ){
2118 sendInference( exp
, n
[j
].eqNode( d_emptyString
), "I_CYCLE" );
2119 return Node::null();
2122 Trace("strings-error") << "Looping term should be congruent : " << n
<< " " << eqc
<< " " << ncy
<< std::endl
;
2123 //should find a non-empty component, otherwise would have been singular congruent (I_Norm_S)
2129 if( hasProcessed() ){
2130 return Node::null();
2140 //now we can add it to the list of equivalence classes
2141 d_strings_eqc
.push_back( eqc
);
2145 return Node::null();
2148 void TheoryStrings::checkNormalFormsEq()
2150 if( !options::stringEagerLen() ){
2151 for( unsigned i
=0; i
<d_strings_eqc
.size(); i
++ ) {
2152 Node eqc
= d_strings_eqc
[i
];
2153 eq::EqClassIterator eqc_i
= eq::EqClassIterator( eqc
, &d_equalityEngine
);
2154 while( !eqc_i
.isFinished() ) {
2156 if( d_congruent
.find( n
)==d_congruent
.end() ){
2157 registerTerm( n
, 2 );
2168 // calculate normal forms for each equivalence class, possibly adding
2170 d_normal_forms
.clear();
2171 d_normal_forms_exp
.clear();
2172 std::map
<Node
, Node
> nf_to_eqc
;
2173 std::map
<Node
, Node
> eqc_to_nf
;
2174 std::map
<Node
, Node
> eqc_to_exp
;
2175 for (const Node
& eqc
: d_strings_eqc
)
2177 Trace("strings-process-debug") << "- Verify normal forms are the same for "
2178 << eqc
<< std::endl
;
2179 normalizeEquivalenceClass(eqc
);
2180 Trace("strings-debug") << "Finished normalizing eqc..." << std::endl
;
2185 Node nf_term
= mkConcat(d_normal_forms
[eqc
]);
2186 std::map
<Node
, Node
>::iterator itn
= nf_to_eqc
.find(nf_term
);
2187 if (itn
!= nf_to_eqc
.end())
2189 // two equivalence classes have same normal form, merge
2190 std::vector
<Node
> nf_exp
;
2191 nf_exp
.push_back(mkAnd(d_normal_forms_exp
[eqc
]));
2192 nf_exp
.push_back(eqc_to_exp
[itn
->second
]);
2194 d_normal_forms_base
[eqc
].eqNode(d_normal_forms_base
[itn
->second
]);
2195 sendInference(nf_exp
, eq
, "Normal_Form");
2196 if( hasProcessed() ){
2202 nf_to_eqc
[nf_term
] = eqc
;
2203 eqc_to_nf
[eqc
] = nf_term
;
2204 eqc_to_exp
[eqc
] = mkAnd(d_normal_forms_exp
[eqc
]);
2206 Trace("strings-process-debug")
2207 << "Done verifying normal forms are the same for " << eqc
<< std::endl
;
2209 if (Trace
.isOn("strings-nf"))
2211 Trace("strings-nf") << "**** Normal forms are : " << std::endl
;
2212 for (std::map
<Node
, Node
>::iterator it
= eqc_to_exp
.begin();
2213 it
!= eqc_to_exp
.end();
2216 Trace("strings-nf") << " N[" << it
->first
<< "] (base "
2217 << d_normal_forms_base
[it
->first
]
2218 << ") = " << eqc_to_nf
[it
->first
] << std::endl
;
2219 Trace("strings-nf") << " exp: " << it
->second
<< std::endl
;
2221 Trace("strings-nf") << std::endl
;
2225 void TheoryStrings::checkCodes()
2227 // ensure that lemmas regarding str.code been added for each constant string
2231 NodeManager
* nm
= NodeManager::currentNM();
2232 // str.code applied to the code term for each equivalence class that has a
2233 // code term but is not a constant
2234 std::vector
<Node
> nconst_codes
;
2235 // str.code applied to the proxy variables for each equivalence classes that
2236 // are constants of size one
2237 std::vector
<Node
> const_codes
;
2238 for (const Node
& eqc
: d_strings_eqc
)
2240 if (d_normal_forms
[eqc
].size() == 1 && d_normal_forms
[eqc
][0].isConst())
2242 Node c
= d_normal_forms
[eqc
][0];
2243 Trace("strings-code-debug") << "Get proxy variable for " << c
2245 Node cc
= nm
->mkNode(kind::STRING_CODE
, c
);
2246 cc
= Rewriter::rewrite(cc
);
2247 Assert(cc
.isConst());
2248 NodeNodeMap::const_iterator it
= d_proxy_var
.find(c
);
2249 AlwaysAssert(it
!= d_proxy_var
.end());
2250 Node vc
= nm
->mkNode(kind::STRING_CODE
, (*it
).second
);
2251 if (!areEqual(cc
, vc
))
2253 sendInference(d_empty_vec
, cc
.eqNode(vc
), "Code_Proxy");
2255 const_codes
.push_back(vc
);
2259 EqcInfo
* ei
= getOrMakeEqcInfo(eqc
, false);
2260 if (ei
&& !ei
->d_code_term
.get().isNull())
2262 Node vc
= nm
->mkNode(kind::STRING_CODE
, ei
->d_code_term
.get());
2263 nconst_codes
.push_back(vc
);
2271 // now, ensure that str.code is injective
2272 std::vector
<Node
> cmps
;
2273 cmps
.insert(cmps
.end(), const_codes
.rbegin(), const_codes
.rend());
2274 cmps
.insert(cmps
.end(), nconst_codes
.rbegin(), nconst_codes
.rend());
2275 for (unsigned i
= 0, num_ncc
= nconst_codes
.size(); i
< num_ncc
; i
++)
2277 Node c1
= nconst_codes
[i
];
2279 for (const Node
& c2
: cmps
)
2281 Trace("strings-code-debug")
2282 << "Compare codes : " << c1
<< " " << c2
<< std::endl
;
2283 if (!areDisequal(c1
, c2
) && !areEqual(c1
, d_neg_one
))
2285 Node eq_no
= c1
.eqNode(d_neg_one
);
2286 Node deq
= c1
.eqNode(c2
).negate();
2287 Node eqn
= c1
[0].eqNode(c2
[0]);
2288 // str.code(x)==-1 V str.code(x)!=str.code(y) V x==y
2289 Node inj_lem
= nm
->mkNode(kind::OR
, eq_no
, deq
, eqn
);
2290 sendInference(d_empty_vec
, inj_lem
, "Code_Inj");
2297 //compute d_normal_forms_(base,exp,exp_depend)[eqc]
2298 void TheoryStrings::normalizeEquivalenceClass( Node eqc
) {
2299 Trace("strings-process-debug") << "Process equivalence class " << eqc
<< std::endl
;
2300 if( areEqual( eqc
, d_emptyString
) ) {
2301 #ifdef CVC4_ASSERTIONS
2302 for( unsigned j
=0; j
<d_eqc
[eqc
].size(); j
++ ){
2303 Node n
= d_eqc
[eqc
][j
];
2304 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ){
2305 Assert( areEqual( n
[i
], d_emptyString
) );
2310 Trace("strings-process-debug") << "Return process equivalence class " << eqc
<< " : empty." << std::endl
;
2311 d_normal_forms_base
[eqc
] = d_emptyString
;
2312 d_normal_forms
[eqc
].clear();
2313 d_normal_forms_exp
[eqc
].clear();
2315 Assert( d_normal_forms
.find(eqc
)==d_normal_forms
.end() );
2316 //phi => t = s1 * ... * sn
2317 // normal form for each non-variable term in this eqc (s1...sn)
2318 std::vector
< std::vector
< Node
> > normal_forms
;
2319 // explanation for each normal form (phi)
2320 std::vector
< std::vector
< Node
> > normal_forms_exp
;
2321 // dependency information
2322 std::vector
< std::map
< Node
, std::map
< bool, int > > > normal_forms_exp_depend
;
2323 // record terms for each normal form (t)
2324 std::vector
< Node
> normal_form_src
;
2326 getNormalForms(eqc
, normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
);
2327 if( hasProcessed() ){
2330 // process the normal forms
2331 processNEqc( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
);
2332 if( hasProcessed() ){
2335 //debugPrintNormalForms( "strings-solve", eqc, normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend );
2337 //construct the normal form
2338 Assert( !normal_forms
.empty() );
2341 std::vector
< Node
>::iterator itn
= std::find( normal_form_src
.begin(), normal_form_src
.end(), eqc
);
2342 if( itn
!=normal_form_src
.end() ){
2343 nf_index
= itn
- normal_form_src
.begin();
2344 Trace("strings-solve-debug2") << "take normal form " << nf_index
<< std::endl
;
2345 Assert( normal_form_src
[nf_index
]==eqc
);
2347 //just take the first normal form
2348 Trace("strings-solve-debug2") << "take the first normal form" << std::endl
;
2350 d_normal_forms
[eqc
].insert( d_normal_forms
[eqc
].end(), normal_forms
[nf_index
].begin(), normal_forms
[nf_index
].end() );
2351 d_normal_forms_exp
[eqc
].insert( d_normal_forms_exp
[eqc
].end(), normal_forms_exp
[nf_index
].begin(), normal_forms_exp
[nf_index
].end() );
2352 Trace("strings-solve-debug2") << "take normal form ... done" << std::endl
;
2353 d_normal_forms_base
[eqc
] = normal_form_src
[nf_index
];
2354 //track dependencies
2355 for( unsigned i
=0; i
<normal_forms_exp
[nf_index
].size(); i
++ ){
2356 Node exp
= normal_forms_exp
[nf_index
][i
];
2357 for( unsigned r
=0; r
<2; r
++ ){
2358 d_normal_forms_exp_depend
[eqc
][exp
][r
==0] = normal_forms_exp_depend
[nf_index
][exp
][r
==0];
2361 Trace("strings-process-debug") << "Return process equivalence class " << eqc
<< " : returned, size = " << d_normal_forms
[eqc
].size() << std::endl
;
2365 void trackNfExpDependency( std::vector
< Node
>& nf_exp_n
, std::map
< Node
, std::map
< bool, int > >& nf_exp_depend_n
, Node exp
, int new_val
, int new_rev_val
){
2366 if( std::find( nf_exp_n
.begin(), nf_exp_n
.end(), exp
)==nf_exp_n
.end() ){
2367 nf_exp_n
.push_back( exp
);
2369 for( unsigned k
=0; k
<2; k
++ ){
2370 int val
= k
==0 ? new_val
: new_rev_val
;
2371 std::map
< bool, int >::iterator itned
= nf_exp_depend_n
[exp
].find( k
==1 );
2372 if( itned
==nf_exp_depend_n
[exp
].end() ){
2373 Trace("strings-process-debug") << "Deps : set dependency on " << exp
<< " to " << val
<< " isRev=" << (k
==0) << std::endl
;
2374 nf_exp_depend_n
[exp
][k
==1] = val
;
2376 Trace("strings-process-debug") << "Deps : Multiple dependencies on " << exp
<< " : " << itned
->second
<< " " << val
<< " isRev=" << (k
==0) << std::endl
;
2377 //if we already have a dependency (in the case of non-linear string equalities), it is min/max
2378 bool cmp
= val
> itned
->second
;
2380 nf_exp_depend_n
[exp
][k
==1] = val
;
2386 void TheoryStrings::getNormalForms( Node
&eqc
, std::vector
< std::vector
< Node
> > &normal_forms
, std::vector
< Node
> &normal_form_src
,
2387 std::vector
< std::vector
< Node
> > &normal_forms_exp
, std::vector
< std::map
< Node
, std::map
< bool, int > > >& normal_forms_exp_depend
) {
2388 //constant for equivalence class
2389 Node eqc_non_c
= eqc
;
2390 Trace("strings-process-debug") << "Get normal forms " << eqc
<< std::endl
;
2391 eq::EqClassIterator eqc_i
= eq::EqClassIterator( eqc
, &d_equalityEngine
);
2392 while( !eqc_i
.isFinished() ){
2394 if( d_congruent
.find( n
)==d_congruent
.end() ){
2395 if( n
.getKind() == kind::CONST_STRING
|| n
.getKind() == kind::STRING_CONCAT
){
2396 Trace("strings-process-debug") << "Get Normal Form : Process term " << n
<< " in eqc " << eqc
<< std::endl
;
2397 std::vector
< Node
> nf_n
;
2398 std::vector
< Node
> nf_exp_n
;
2399 std::map
< Node
, std::map
< bool, int > > nf_exp_depend_n
;
2400 if( n
.getKind()==kind::CONST_STRING
){
2401 if( n
!=d_emptyString
) {
2402 nf_n
.push_back( n
);
2404 }else if( n
.getKind()==kind::STRING_CONCAT
){
2405 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ) {
2406 Node nr
= d_equalityEngine
.getRepresentative( n
[i
] );
2407 Trace("strings-process-debug") << "Normalizing subterm " << n
[i
] << " = " << nr
<< std::endl
;
2408 Assert( d_normal_forms
.find( nr
)!=d_normal_forms
.end() );
2409 unsigned orig_size
= nf_n
.size();
2410 unsigned add_size
= d_normal_forms
[nr
].size();
2411 //if not the empty string, add to current normal form
2412 if( !d_normal_forms
[nr
].empty() ){
2413 for( unsigned r
=0; r
<d_normal_forms
[nr
].size(); r
++ ) {
2414 if( Trace
.isOn("strings-error") ) {
2415 if( d_normal_forms
[nr
][r
].getKind()==kind::STRING_CONCAT
){
2416 Trace("strings-error") << "Strings::Error: From eqc = " << eqc
<< ", " << n
<< " index " << i
<< ", bad normal form : ";
2417 for( unsigned rr
=0; rr
<d_normal_forms
[nr
].size(); rr
++ ) {
2418 Trace("strings-error") << d_normal_forms
[nr
][rr
] << " ";
2420 Trace("strings-error") << std::endl
;
2423 Assert( d_normal_forms
[nr
][r
].getKind()!=kind::STRING_CONCAT
);
2425 nf_n
.insert( nf_n
.end(), d_normal_forms
[nr
].begin(), d_normal_forms
[nr
].end() );
2428 for( unsigned j
=0; j
<d_normal_forms_exp
[nr
].size(); j
++ ){
2429 Node exp
= d_normal_forms_exp
[nr
][j
];
2431 trackNfExpDependency( nf_exp_n
, nf_exp_depend_n
, exp
,
2432 orig_size
+ d_normal_forms_exp_depend
[nr
][exp
][false],
2433 orig_size
+ ( add_size
- d_normal_forms_exp_depend
[nr
][exp
][true] ) );
2435 if( d_normal_forms_base
[nr
]!=n
[i
] ){
2436 Assert( d_normal_forms_base
.find( nr
)!=d_normal_forms_base
.end() );
2437 Node eq
= n
[i
].eqNode( d_normal_forms_base
[nr
] );
2438 //track depends : entire current segment is dependent upon base equality
2439 trackNfExpDependency( nf_exp_n
, nf_exp_depend_n
, eq
, orig_size
, orig_size
+ add_size
);
2442 //convert forward indices to reverse indices
2443 int total_size
= nf_n
.size();
2444 for( std::map
< Node
, std::map
< bool, int > >::iterator it
= nf_exp_depend_n
.begin(); it
!= nf_exp_depend_n
.end(); ++it
){
2445 it
->second
[true] = total_size
- it
->second
[true];
2446 Assert( it
->second
[true]>=0 );
2449 //if not equal to self
2450 if( nf_n
.size()>1 || ( nf_n
.size()==1 && nf_n
[0].getKind()==kind::CONST_STRING
) ){
2451 if( nf_n
.size()>1 ) {
2452 for( unsigned i
=0; i
<nf_n
.size(); i
++ ){
2453 if( Trace
.isOn("strings-error") ){
2454 Trace("strings-error") << "Cycle for normal form ";
2455 printConcat(nf_n
,"strings-error");
2456 Trace("strings-error") << "..." << nf_n
[i
] << std::endl
;
2458 Assert( !areEqual( nf_n
[i
], n
) );
2461 normal_forms
.push_back(nf_n
);
2462 normal_form_src
.push_back(n
);
2463 normal_forms_exp
.push_back(nf_exp_n
);
2464 normal_forms_exp_depend
.push_back(nf_exp_depend_n
);
2466 //this was redundant: combination of self + empty string(s)
2467 Node nn
= nf_n
.size()==0 ? d_emptyString
: nf_n
[0];
2468 Assert( areEqual( nn
, eqc
) );
2477 if( normal_forms
.empty() ) {
2478 Trace("strings-solve-debug2") << "construct the normal form" << std::endl
;
2479 //do not choose a concat here use "eqc_non_c" (in this case they have non-trivial explanation why they normalize to self)
2480 std::vector
< Node
> eqc_non_c_nf
;
2481 getConcatVec( eqc_non_c
, eqc_non_c_nf
);
2482 normal_forms
.push_back( eqc_non_c_nf
);
2483 normal_form_src
.push_back( eqc_non_c
);
2484 normal_forms_exp
.push_back( std::vector
< Node
>() );
2485 normal_forms_exp_depend
.push_back( std::map
< Node
, std::map
< bool, int > >() );
2487 if(Trace
.isOn("strings-solve")) {
2488 Trace("strings-solve") << "--- Normal forms for equivalance class " << eqc
<< " : " << std::endl
;
2489 for( unsigned i
=0; i
<normal_forms
.size(); i
++ ) {
2490 Trace("strings-solve") << "#" << i
<< " (from " << normal_form_src
[i
] << ") : ";
2491 for( unsigned j
=0; j
<normal_forms
[i
].size(); j
++ ) {
2493 Trace("strings-solve") << ", ";
2495 Trace("strings-solve") << normal_forms
[i
][j
];
2497 Trace("strings-solve") << std::endl
;
2498 Trace("strings-solve") << " Explanation is : ";
2499 if(normal_forms_exp
[i
].size() == 0) {
2500 Trace("strings-solve") << "NONE";
2502 for( unsigned j
=0; j
<normal_forms_exp
[i
].size(); j
++ ) {
2504 Trace("strings-solve") << " AND ";
2506 Trace("strings-solve") << normal_forms_exp
[i
][j
];
2508 Trace("strings-solve") << std::endl
;
2509 Trace("strings-solve") << "WITH DEPENDENCIES : " << std::endl
;
2510 for( unsigned j
=0; j
<normal_forms_exp
[i
].size(); j
++ ) {
2511 Trace("strings-solve") << " " << normal_forms_exp
[i
][j
] << " -> ";
2512 Trace("strings-solve") << normal_forms_exp_depend
[i
][normal_forms_exp
[i
][j
]][false] << ",";
2513 Trace("strings-solve") << normal_forms_exp_depend
[i
][normal_forms_exp
[i
][j
]][true] << std::endl
;
2516 Trace("strings-solve") << std::endl
;
2520 Trace("strings-solve") << "--- Single normal form for equivalence class " << eqc
<< std::endl
;
2523 //if equivalence class is constant, approximate as containment, infer conflicts
2524 Node c
= getConstantEqc( eqc
);
2526 Trace("strings-solve") << "Eqc is constant " << c
<< std::endl
;
2527 for( unsigned i
=0; i
<normal_forms
.size(); i
++ ) {
2529 if( !TheoryStringsRewriter::canConstantContainList( c
, normal_forms
[i
], firstc
, lastc
) ){
2530 Node n
= normal_form_src
[i
];
2532 Trace("strings-solve") << "Normal form for " << n
<< " cannot be contained in constant " << c
<< std::endl
;
2533 //conflict, explanation is n = base ^ base = c ^ relevant porition of ( n = N[n] )
2534 std::vector
< Node
> exp
;
2535 Assert( d_eqc_to_const_base
.find( eqc
)!=d_eqc_to_const_base
.end() );
2536 addToExplanation( n
, d_eqc_to_const_base
[eqc
], exp
);
2537 Assert( d_eqc_to_const_exp
.find( eqc
)!=d_eqc_to_const_exp
.end() );
2538 if( !d_eqc_to_const_exp
[eqc
].isNull() ){
2539 exp
.push_back( d_eqc_to_const_exp
[eqc
] );
2541 //TODO: this can be minimized based on firstc/lastc, normal_forms_exp_depend
2542 exp
.insert( exp
.end(), normal_forms_exp
[i
].begin(), normal_forms_exp
[i
].end() );
2543 Node conc
= d_false
;
2544 sendInference( exp
, conc
, "N_NCTN" );
2551 void TheoryStrings::getExplanationVectorForPrefix( std::vector
< std::vector
< Node
> > &normal_forms_exp
, std::vector
< std::map
< Node
, std::map
< bool, int > > >& normal_forms_exp_depend
,
2552 unsigned i
, int index
, bool isRev
, std::vector
< Node
>& curr_exp
) {
2553 if( index
==-1 || !options::stringMinPrefixExplain() ){
2554 curr_exp
.insert(curr_exp
.end(), normal_forms_exp
[i
].begin(), normal_forms_exp
[i
].end() );
2556 for( unsigned k
=0; k
<normal_forms_exp
[i
].size(); k
++ ){
2557 Node exp
= normal_forms_exp
[i
][k
];
2558 int dep
= normal_forms_exp_depend
[i
][exp
][isRev
];
2560 curr_exp
.push_back( exp
);
2561 Trace("strings-explain-prefix-debug") << " include : " << exp
<< std::endl
;
2563 Trace("strings-explain-prefix-debug") << " exclude : " << exp
<< std::endl
;
2569 void TheoryStrings::getExplanationVectorForPrefixEq( std::vector
< std::vector
< Node
> > &normal_forms
, std::vector
< Node
> &normal_form_src
,
2570 std::vector
< std::vector
< Node
> > &normal_forms_exp
, std::vector
< std::map
< Node
, std::map
< bool, int > > >& normal_forms_exp_depend
,
2571 unsigned i
, unsigned j
, int index_i
, int index_j
, bool isRev
, std::vector
< Node
>& curr_exp
) {
2572 Trace("strings-explain-prefix") << "Get explanation for prefix " << index_i
<< ", " << index_j
<< " of normal forms " << i
<< " and " << j
<< ", reverse = " << isRev
<< std::endl
;
2573 for( unsigned r
=0; r
<2; r
++ ){
2574 getExplanationVectorForPrefix( normal_forms_exp
, normal_forms_exp_depend
, r
==0 ? i
: j
, r
==0 ? index_i
: index_j
, isRev
, curr_exp
);
2576 Trace("strings-explain-prefix") << "Included " << curr_exp
.size() << " / " << ( normal_forms_exp
[i
].size() + normal_forms_exp
[j
].size() ) << std::endl
;
2577 addToExplanation( normal_form_src
[i
], normal_form_src
[j
], curr_exp
);
2581 void TheoryStrings::processNEqc( std::vector
< std::vector
< Node
> > &normal_forms
, std::vector
< Node
> &normal_form_src
,
2582 std::vector
< std::vector
< Node
> > &normal_forms_exp
, std::vector
< std::map
< Node
, std::map
< bool, int > > >& normal_forms_exp_depend
){
2583 //the possible inferences
2584 std::vector
< InferInfo
> pinfer
;
2585 // loop over all pairs
2586 for(unsigned i
=0; i
<normal_forms
.size()-1; i
++) {
2587 //unify each normalform[j] with normal_forms[i]
2588 for(unsigned j
=i
+1; j
<normal_forms
.size(); j
++ ) {
2589 //ensure that normal_forms[i] and normal_forms[j] are the same modulo equality, add to pinfer if not
2590 Trace("strings-solve") << "Strings: Process normal form #" << i
<< " against #" << j
<< "..." << std::endl
;
2591 if( isNormalFormPair( normal_form_src
[i
], normal_form_src
[j
] ) ) {
2592 Trace("strings-solve") << "Strings: Already cached." << std::endl
;
2594 //process the reverse direction first (check for easy conflicts and inferences)
2595 unsigned rindex
= 0;
2596 processReverseNEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, rindex
, 0, pinfer
);
2597 if( hasProcessed() ){
2599 }else if( !pinfer
.empty() && pinfer
.back().d_id
==1 ){
2602 //AJR: for less aggressive endpoint inference
2606 processSimpleNEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, index
, false, rindex
, pinfer
);
2607 if( hasProcessed() ){
2609 }else if( !pinfer
.empty() && pinfer
.back().d_id
==1 ){
2615 if( !pinfer
.empty() ){
2616 //now, determine which of the possible inferences we want to add
2618 Trace("strings-solve") << "Possible inferences (" << pinfer
.size() << ") : " << std::endl
;
2619 unsigned min_id
= 9;
2620 unsigned max_index
= 0;
2621 for (unsigned i
= 0, size
= pinfer
.size(); i
< size
; i
++)
2623 Trace("strings-solve") << "From " << pinfer
[i
].d_i
<< " / " << pinfer
[i
].d_j
<< " (rev=" << pinfer
[i
].d_rev
<< ") : ";
2624 Trace("strings-solve")
2625 << pinfer
[i
].d_conc
<< " by " << pinfer
[i
].d_id
<< std::endl
;
2626 if( use_index
==-1 || pinfer
[i
].d_id
<min_id
|| ( pinfer
[i
].d_id
==min_id
&& pinfer
[i
].d_index
>max_index
) ){
2627 min_id
= pinfer
[i
].d_id
;
2628 max_index
= pinfer
[i
].d_index
;
2632 //send the inference
2633 if( !pinfer
[use_index
].d_nf_pair
[0].isNull() ){
2634 Assert( !pinfer
[use_index
].d_nf_pair
[1].isNull() );
2635 addNormalFormPair( pinfer
[use_index
].d_nf_pair
[0], pinfer
[use_index
].d_nf_pair
[1] );
2637 std::stringstream ssi
;
2638 ssi
<< pinfer
[use_index
].d_id
;
2639 sendInference(pinfer
[use_index
].d_ant
,
2640 pinfer
[use_index
].d_antn
,
2641 pinfer
[use_index
].d_conc
,
2643 pinfer
[use_index
].sendAsLemma());
2644 for( std::map
< int, std::vector
< Node
> >::iterator it
= pinfer
[use_index
].d_new_skolem
.begin(); it
!= pinfer
[use_index
].d_new_skolem
.end(); ++it
){
2645 for( unsigned i
=0; i
<it
->second
.size(); i
++ ){
2647 sendLengthLemma( it
->second
[i
] );
2648 }else if( it
->first
==1 ){
2649 registerNonEmptySkolem( it
->second
[i
] );
2656 bool TheoryStrings::InferInfo::sendAsLemma() {
2660 void TheoryStrings::processReverseNEq( std::vector
< std::vector
< Node
> > &normal_forms
, std::vector
< Node
> &normal_form_src
,
2661 std::vector
< std::vector
< Node
> > &normal_forms_exp
, std::vector
< std::map
< Node
, std::map
< bool, int > > >& normal_forms_exp_depend
,
2662 unsigned i
, unsigned j
, unsigned& index
, unsigned rproc
, std::vector
< InferInfo
>& pinfer
) {
2663 //reverse normal form of i, j
2664 std::reverse( normal_forms
[i
].begin(), normal_forms
[i
].end() );
2665 std::reverse( normal_forms
[j
].begin(), normal_forms
[j
].end() );
2667 processSimpleNEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, index
, true, rproc
, pinfer
);
2669 //reverse normal form of i, j
2670 std::reverse( normal_forms
[i
].begin(), normal_forms
[i
].end() );
2671 std::reverse( normal_forms
[j
].begin(), normal_forms
[j
].end() );
2674 //rproc is the # is the size of suffix that is identical
2675 void TheoryStrings::processSimpleNEq( std::vector
< std::vector
< Node
> > &normal_forms
, std::vector
< Node
> &normal_form_src
,
2676 std::vector
< std::vector
< Node
> > &normal_forms_exp
, std::vector
< std::map
< Node
, std::map
< bool, int > > >& normal_forms_exp_depend
,
2677 unsigned i
, unsigned j
, unsigned& index
, bool isRev
, unsigned rproc
, std::vector
< InferInfo
>& pinfer
) {
2678 Assert( rproc
<=normal_forms
[i
].size() && rproc
<=normal_forms
[j
].size() );
2682 //if we are at the end
2683 if( index
==(normal_forms
[i
].size()-rproc
) || index
==(normal_forms
[j
].size()-rproc
) ){
2684 if( index
==(normal_forms
[i
].size()-rproc
) && index
==(normal_forms
[j
].size()-rproc
) ){
2687 //the remainder must be empty
2688 unsigned k
= index
==(normal_forms
[i
].size()-rproc
) ? j
: i
;
2689 unsigned index_k
= index
;
2690 //Node eq_exp = mkAnd( curr_exp );
2691 std::vector
< Node
> curr_exp
;
2692 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, -1, -1, isRev
, curr_exp
);
2693 while( !d_conflict
&& index_k
<(normal_forms
[k
].size()-rproc
) ){
2694 //can infer that this string must be empty
2695 Node eq
= normal_forms
[k
][index_k
].eqNode( d_emptyString
);
2696 //Trace("strings-lemma") << "Strings: Infer " << eq << " from " << eq_exp << std::endl;
2697 Assert( !areEqual( d_emptyString
, normal_forms
[k
][index_k
] ) );
2698 sendInference( curr_exp
, eq
, "N_EndpointEmp" );
2703 Trace("strings-solve-debug") << "Process " << normal_forms
[i
][index
] << " ... " << normal_forms
[j
][index
] << std::endl
;
2704 if( normal_forms
[i
][index
]==normal_forms
[j
][index
] ){
2705 Trace("strings-solve-debug") << "Simple Case 1 : strings are equal" << std::endl
;
2709 Assert( !areEqual(normal_forms
[i
][index
], normal_forms
[j
][index
]) );
2710 std::vector
< Node
> temp_exp
;
2711 Node length_term_i
= getLength( normal_forms
[i
][index
], temp_exp
);
2712 Node length_term_j
= getLength( normal_forms
[j
][index
], temp_exp
);
2713 //check length(normal_forms[i][index]) == length(normal_forms[j][index])
2714 if( areEqual( length_term_i
, length_term_j
) ){
2715 Trace("strings-solve-debug") << "Simple Case 2 : string lengths are equal" << std::endl
;
2716 Node eq
= normal_forms
[i
][index
].eqNode( normal_forms
[j
][index
] );
2717 //eq = Rewriter::rewrite( eq );
2718 Node length_eq
= length_term_i
.eqNode( length_term_j
);
2719 //temp_exp.insert(temp_exp.end(), curr_exp.begin(), curr_exp.end() );
2720 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, index
, index
, isRev
, temp_exp
);
2721 temp_exp
.push_back(length_eq
);
2722 sendInference( temp_exp
, eq
, "N_Unify" );
2724 }else if( ( normal_forms
[i
][index
].getKind()!=kind::CONST_STRING
&& index
==normal_forms
[i
].size()-rproc
-1 ) ||
2725 ( normal_forms
[j
][index
].getKind()!=kind::CONST_STRING
&& index
==normal_forms
[j
].size()-rproc
-1 ) ){
2726 Trace("strings-solve-debug") << "Simple Case 3 : at endpoint" << std::endl
;
2727 std::vector
< Node
> antec
;
2728 //antec.insert(antec.end(), curr_exp.begin(), curr_exp.end() );
2729 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, -1, -1, isRev
, antec
);
2730 std::vector
< Node
> eqn
;
2731 for( unsigned r
=0; r
<2; r
++ ) {
2732 int index_k
= index
;
2733 int k
= r
==0 ? i
: j
;
2734 std::vector
< Node
> eqnc
;
2735 for( unsigned index_l
=index_k
; index_l
<(normal_forms
[k
].size()-rproc
); index_l
++ ) {
2737 eqnc
.insert(eqnc
.begin(), normal_forms
[k
][index_l
] );
2739 eqnc
.push_back( normal_forms
[k
][index_l
] );
2742 eqn
.push_back( mkConcat( eqnc
) );
2744 if( !areEqual( eqn
[0], eqn
[1] ) ){
2745 sendInference( antec
, eqn
[0].eqNode( eqn
[1] ), "N_EndpointEq", true );
2748 Assert( normal_forms
[i
].size()==normal_forms
[j
].size() );
2749 index
= normal_forms
[i
].size()-rproc
;
2751 }else if( normal_forms
[i
][index
].isConst() && normal_forms
[j
][index
].isConst() ){
2752 Node const_str
= normal_forms
[i
][index
];
2753 Node other_str
= normal_forms
[j
][index
];
2754 Trace("strings-solve-debug") << "Simple Case 3 : Const Split : " << const_str
<< " vs " << other_str
<< " at index " << index
<< ", isRev = " << isRev
<< std::endl
;
2755 unsigned len_short
= const_str
.getConst
<String
>().size() <= other_str
.getConst
<String
>().size() ? const_str
.getConst
<String
>().size() : other_str
.getConst
<String
>().size();
2756 bool isSameFix
= isRev
? const_str
.getConst
<String
>().rstrncmp(other_str
.getConst
<String
>(), len_short
): const_str
.getConst
<String
>().strncmp(other_str
.getConst
<String
>(), len_short
);
2758 //same prefix/suffix
2759 //k is the index of the string that is shorter
2760 int k
= const_str
.getConst
<String
>().size()<other_str
.getConst
<String
>().size() ? i
: j
;
2761 int l
= const_str
.getConst
<String
>().size()<other_str
.getConst
<String
>().size() ? j
: i
;
2762 //update the nf exp dependencies
2763 //notice this is not critical for soundness: not doing the below incrementing will only lead to overapproximating when antecedants are required in explanations
2764 for( std::map
< Node
, std::map
< bool, int > >::iterator itnd
= normal_forms_exp_depend
[l
].begin(); itnd
!= normal_forms_exp_depend
[l
].end(); ++itnd
){
2765 for( std::map
< bool, int >::iterator itnd2
= itnd
->second
.begin(); itnd2
!= itnd
->second
.end(); ++itnd2
){
2766 //see if this can be incremented: it can if it is not relevant to the current index
2767 Assert( itnd2
->second
>=0 && itnd2
->second
<=(int)normal_forms
[l
].size() );
2768 bool increment
= (itnd2
->first
==isRev
) ? itnd2
->second
>(int)index
: ( (int)normal_forms
[l
].size()-1-itnd2
->second
)<(int)index
;
2770 normal_forms_exp_depend
[l
][itnd
->first
][itnd2
->first
] = itnd2
->second
+ 1;
2775 int new_len
= normal_forms
[l
][index
].getConst
<String
>().size() - len_short
;
2776 Node remainderStr
= NodeManager::currentNM()->mkConst( normal_forms
[l
][index
].getConst
<String
>().substr(0, new_len
) );
2777 Trace("strings-solve-debug-test") << "Break normal form of " << normal_forms
[l
][index
] << " into " << normal_forms
[k
][index
] << ", " << remainderStr
<< std::endl
;
2778 normal_forms
[l
].insert( normal_forms
[l
].begin()+index
+ 1, remainderStr
);
2780 Node remainderStr
= NodeManager::currentNM()->mkConst(normal_forms
[l
][index
].getConst
<String
>().substr(len_short
));
2781 Trace("strings-solve-debug-test") << "Break normal form of " << normal_forms
[l
][index
] << " into " << normal_forms
[k
][index
] << ", " << remainderStr
<< std::endl
;
2782 normal_forms
[l
].insert( normal_forms
[l
].begin()+index
+ 1, remainderStr
);
2784 normal_forms
[l
][index
] = normal_forms
[k
][index
];
2789 std::vector
< Node
> antec
;
2790 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, index
, index
, isRev
, antec
);
2791 sendInference( antec
, d_false
, "N_Const", true );
2795 //construct the candidate inference "info"
2797 info
.d_index
= index
;
2802 bool info_valid
= false;
2803 Assert( index
<normal_forms
[i
].size()-rproc
&& index
<normal_forms
[j
].size()-rproc
);
2804 std::vector
< Node
> lexp
;
2805 Node length_term_i
= getLength( normal_forms
[i
][index
], lexp
);
2806 Node length_term_j
= getLength( normal_forms
[j
][index
], lexp
);
2807 //split on equality between string lengths (note that splitting on equality between strings is worse since it is harder to process)
2808 if( !areDisequal( length_term_i
, length_term_j
) && !areEqual( length_term_i
, length_term_j
) &&
2809 normal_forms
[i
][index
].getKind()!=kind::CONST_STRING
&& normal_forms
[j
][index
].getKind()!=kind::CONST_STRING
){ //AJR: remove the latter 2 conditions?
2810 Trace("strings-solve-debug") << "Non-simple Case 1 : string lengths neither equal nor disequal" << std::endl
;
2811 //try to make the lengths equal via splitting on demand
2812 Node length_eq
= NodeManager::currentNM()->mkNode( kind::EQUAL
, length_term_i
, length_term_j
);
2813 length_eq
= Rewriter::rewrite( length_eq
);
2815 info
.d_conc
= NodeManager::currentNM()->mkNode( kind::OR
, length_eq
, length_eq
.negate() );
2816 info
.d_pending_phase
[ length_eq
] = true;
2817 info
.d_id
= INFER_LEN_SPLIT
;
2820 Trace("strings-solve-debug") << "Non-simple Case 2 : must compare strings" << std::endl
;
2823 if( detectLoop( normal_forms
, i
, j
, index
, loop_in_i
, loop_in_j
, rproc
) ){
2824 if( !isRev
){ //FIXME
2825 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, -1, -1, isRev
, info
.d_ant
);
2827 if( processLoop( normal_forms
, normal_form_src
, i
, j
, loop_in_i
!=-1 ? i
: j
, loop_in_i
!=-1 ? j
: i
, loop_in_i
!=-1 ? loop_in_i
: loop_in_j
, index
, info
) ){
2832 //AJR: length entailment here?
2833 if( normal_forms
[i
][index
].getKind() == kind::CONST_STRING
|| normal_forms
[j
][index
].getKind() == kind::CONST_STRING
){
2834 unsigned const_k
= normal_forms
[i
][index
].getKind() == kind::CONST_STRING
? i
: j
;
2835 unsigned nconst_k
= normal_forms
[i
][index
].getKind() == kind::CONST_STRING
? j
: i
;
2836 Node other_str
= normal_forms
[nconst_k
][index
];
2837 Assert( other_str
.getKind()!=kind::CONST_STRING
, "Other string is not constant." );
2838 Assert( other_str
.getKind()!=kind::STRING_CONCAT
, "Other string is not CONCAT." );
2839 if( !d_equalityEngine
.areDisequal( other_str
, d_emptyString
, true ) ){
2840 Node eq
= other_str
.eqNode( d_emptyString
);
2842 info
.d_conc
= NodeManager::currentNM()->mkNode( kind::OR
, eq
, eq
.negate() );
2843 info
.d_id
= INFER_LEN_SPLIT_EMP
;
2846 if( !isRev
){ //FIXME
2847 Node xnz
= other_str
.eqNode( d_emptyString
).negate();
2848 unsigned index_nc_k
= index
+1;
2849 //Node next_const_str = TheoryStringsRewriter::collectConstantStringAt( normal_forms[nconst_k], index_nc_k, false );
2850 unsigned start_index_nc_k
= index
+1;
2851 Node next_const_str
= TheoryStringsRewriter::getNextConstantAt( normal_forms
[nconst_k
], start_index_nc_k
, index_nc_k
, false );
2852 if( !next_const_str
.isNull() ) {
2853 unsigned index_c_k
= index
;
2854 Node const_str
= TheoryStringsRewriter::collectConstantStringAt( normal_forms
[const_k
], index_c_k
, false );
2855 Assert( !const_str
.isNull() );
2856 CVC4::String stra
= const_str
.getConst
<String
>();
2857 CVC4::String strb
= next_const_str
.getConst
<String
>();
2858 //since non-empty, we start with charecter #1
2861 CVC4::String stra1
= stra
.prefix( stra
.size()-1 );
2862 p
= stra
.size() - stra1
.roverlap(strb
);
2863 Trace("strings-csp-debug") << "Compute roverlap : " << const_str
<< " " << next_const_str
<< std::endl
;
2864 size_t p2
= stra1
.rfind(strb
);
2865 p
= p2
==std::string::npos
? p
: ( p
>p2
+1? p2
+1 : p
);
2866 Trace("strings-csp-debug") << "overlap : " << stra1
<< " " << strb
<< " returned " << p
<< " " << p2
<< " " << (p2
==std::string::npos
) << std::endl
;
2868 CVC4::String stra1
= stra
.substr( 1 );
2869 p
= stra
.size() - stra1
.overlap(strb
);
2870 Trace("strings-csp-debug") << "Compute overlap : " << const_str
<< " " << next_const_str
<< std::endl
;
2871 size_t p2
= stra1
.find(strb
);
2872 p
= p2
==std::string::npos
? p
: ( p
>p2
+1? p2
+1 : p
);
2873 Trace("strings-csp-debug") << "overlap : " << stra1
<< " " << strb
<< " returned " << p
<< " " << p2
<< " " << (p2
==std::string::npos
) << std::endl
;
2876 if( start_index_nc_k
==index
+1 ){
2877 info
.d_ant
.push_back( xnz
);
2878 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
,
2879 const_k
, nconst_k
, index_c_k
, index_nc_k
, isRev
, info
.d_ant
);
2880 Node prea
= p
==stra
.size() ? const_str
: NodeManager::currentNM()->mkConst( isRev
? stra
.suffix( p
) : stra
.prefix( p
) );
2881 Node sk
= mkSkolemCached( other_str
, prea
, isRev
? sk_id_c_spt_rev
: sk_id_c_spt
, "c_spt", -1 );
2882 Trace("strings-csp") << "Const Split: " << prea
<< " is removed from " << stra
<< " due to " << strb
<< ", p=" << p
<< std::endl
;
2884 info
.d_conc
= other_str
.eqNode( isRev
? mkConcat( sk
, prea
) : mkConcat(prea
, sk
) );
2885 info
.d_new_skolem
[0].push_back( sk
);
2886 info
.d_id
= INFER_SSPLIT_CST_PROP
;
2889 /* FIXME for isRev, speculative
2890 else if( options::stringLenPropCsp() ){
2891 //propagate length constraint
2892 std::vector< Node > cc;
2893 for( unsigned i=index; i<start_index_nc_k; i++ ){
2894 cc.push_back( normal_forms[nconst_k][i] );
2896 Node lt = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, mkConcat( cc ) );
2897 conc = NodeManager::currentNM()->mkNode( kind::GEQ, lt, NodeManager::currentNM()->mkConst( Rational(p) ) );
2898 sendInference( ant, conc, "S-Split(CSP-P)-lprop", true );
2904 info
.d_ant
.push_back( xnz
);
2905 Node const_str
= normal_forms
[const_k
][index
];
2906 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, index
, index
, isRev
, info
.d_ant
);
2907 CVC4::String stra
= const_str
.getConst
<String
>();
2908 if( options::stringBinaryCsp() && stra
.size()>3 ){
2909 //split string in half
2910 Node c_firstHalf
= NodeManager::currentNM()->mkConst( isRev
? stra
.substr( stra
.size()/2 ) : stra
.substr(0, stra
.size()/2 ) );
2911 Node sk
= mkSkolemCached( other_str
, c_firstHalf
, isRev
? sk_id_vc_bin_spt_rev
: sk_id_vc_bin_spt
, "cb_spt", -1 );
2912 Trace("strings-csp") << "Const Split: " << c_firstHalf
<< " is removed from " << const_str
<< " (binary) " << std::endl
;
2913 info
.d_conc
= NodeManager::currentNM()->mkNode( kind::OR
, other_str
.eqNode( isRev
? mkConcat( sk
, c_firstHalf
) : mkConcat( c_firstHalf
, sk
) ),
2914 NodeManager::currentNM()->mkNode( kind::AND
,
2915 sk
.eqNode( d_emptyString
).negate(),
2916 c_firstHalf
.eqNode( isRev
? mkConcat( sk
, other_str
) : mkConcat( other_str
, sk
) ) ) );
2917 info
.d_new_skolem
[0].push_back( sk
);
2918 info
.d_id
= INFER_SSPLIT_CST_BINARY
;
2922 Node firstChar
= stra
.size() == 1 ? const_str
: NodeManager::currentNM()->mkConst( isRev
? stra
.suffix( 1 ) : stra
.prefix( 1 ) );
2923 Node sk
= mkSkolemCached( other_str
, firstChar
, isRev
? sk_id_vc_spt_rev
: sk_id_vc_spt
, "c_spt", -1 );
2924 Trace("strings-csp") << "Const Split: " << firstChar
<< " is removed from " << const_str
<< " (serial) " << std::endl
;
2925 info
.d_conc
= other_str
.eqNode( isRev
? mkConcat( sk
, firstChar
) : mkConcat(firstChar
, sk
) );
2926 info
.d_new_skolem
[0].push_back( sk
);
2927 info
.d_id
= INFER_SSPLIT_CST
;
2934 int lentTestSuccess
= -1;
2936 if( options::stringCheckEntailLen() ){
2938 for( unsigned e
=0; e
<2; e
++ ){
2939 Node t
= e
==0 ? normal_forms
[i
][index
] : normal_forms
[j
][index
];
2940 //do not infer constants are larger than variables
2941 if( t
.getKind()!=kind::CONST_STRING
){
2942 Node lt1
= e
==0 ? length_term_i
: length_term_j
;
2943 Node lt2
= e
==0 ? length_term_j
: length_term_i
;
2944 Node ent_lit
= Rewriter::rewrite( NodeManager::currentNM()->mkNode( kind::GT
, lt1
, lt2
) );
2945 std::pair
<bool, Node
> et
= d_valuation
.entailmentCheck( THEORY_OF_TYPE_BASED
, ent_lit
);
2947 Trace("strings-entail") << "Strings entailment : " << ent_lit
<< " is entailed in the current context." << std::endl
;
2948 Trace("strings-entail") << " explanation was : " << et
.second
<< std::endl
;
2949 lentTestSuccess
= e
;
2950 lentTestExp
= et
.second
;
2957 getExplanationVectorForPrefixEq( normal_forms
, normal_form_src
, normal_forms_exp
, normal_forms_exp_depend
, i
, j
, index
, index
, isRev
, info
.d_ant
);
2959 for(unsigned xory
=0; xory
<2; xory
++) {
2960 Node x
= xory
==0 ? normal_forms
[i
][index
] : normal_forms
[j
][index
];
2961 Node xgtz
= x
.eqNode( d_emptyString
).negate();
2962 if( d_equalityEngine
.areDisequal( x
, d_emptyString
, true ) ) {
2963 info
.d_ant
.push_back( xgtz
);
2965 info
.d_antn
.push_back( xgtz
);
2968 Node sk
= mkSkolemCached( normal_forms
[i
][index
], normal_forms
[j
][index
], isRev
? sk_id_v_spt_rev
: sk_id_v_spt
, "v_spt", -1 );
2969 //must add length requirement
2970 info
.d_new_skolem
[1].push_back( sk
);
2971 Node eq1
= normal_forms
[i
][index
].eqNode( isRev
? mkConcat(sk
, normal_forms
[j
][index
]) : mkConcat(normal_forms
[j
][index
], sk
) );
2972 Node eq2
= normal_forms
[j
][index
].eqNode( isRev
? mkConcat(sk
, normal_forms
[i
][index
]) : mkConcat(normal_forms
[i
][index
], sk
) );
2974 if( lentTestSuccess
!=-1 ){
2975 info
.d_antn
.push_back( lentTestExp
);
2976 info
.d_conc
= lentTestSuccess
==0 ? eq1
: eq2
;
2977 info
.d_id
= INFER_SSPLIT_VAR_PROP
;
2980 Node ldeq
= NodeManager::currentNM()->mkNode( kind::EQUAL
, length_term_i
, length_term_j
).negate();
2981 if( d_equalityEngine
.areDisequal( length_term_i
, length_term_j
, true ) ){
2982 info
.d_ant
.push_back( ldeq
);
2984 info
.d_antn
.push_back(ldeq
);
2987 info
.d_conc
= NodeManager::currentNM()->mkNode( kind::OR
, eq1
, eq2
);
2988 info
.d_id
= INFER_SSPLIT_VAR
;
2995 pinfer
.push_back( info
);
3004 bool TheoryStrings::detectLoop( std::vector
< std::vector
< Node
> > &normal_forms
, int i
, int j
, int index
, int &loop_in_i
, int &loop_in_j
, unsigned rproc
){
3005 int has_loop
[2] = { -1, -1 };
3006 if( options::stringLB() != 2 ) {
3007 for( unsigned r
=0; r
<2; r
++ ) {
3008 int n_index
= (r
==0 ? i
: j
);
3009 int other_n_index
= (r
==0 ? j
: i
);
3010 if( normal_forms
[other_n_index
][index
].getKind() != kind::CONST_STRING
) {
3011 for( unsigned lp
= index
+1; lp
<normal_forms
[n_index
].size()-rproc
; lp
++ ){
3012 if( normal_forms
[n_index
][lp
]==normal_forms
[other_n_index
][index
] ){
3020 if( has_loop
[0]!=-1 || has_loop
[1]!=-1 ) {
3021 loop_in_i
= has_loop
[0];
3022 loop_in_j
= has_loop
[1];
3025 Trace("strings-solve-debug") << "No loops detected." << std::endl
;
3031 bool TheoryStrings::processLoop( std::vector
< std::vector
< Node
> > &normal_forms
, std::vector
< Node
> &normal_form_src
,
3032 int i
, int j
, int loop_n_index
, int other_n_index
, int loop_index
, int index
, InferInfo
& info
){
3033 if( options::stringAbortLoop() ){
3034 std::stringstream ss
;
3035 ss
<< "Looping word equation encountered." << std::endl
;
3036 throw LogicException(ss
.str());
3038 NodeManager
* nm
= NodeManager::currentNM();
3040 Trace("strings-loop") << "Detected possible loop for "
3041 << normal_forms
[loop_n_index
][loop_index
] << std::endl
;
3042 Trace("strings-loop") << " ... (X)= " << normal_forms
[other_n_index
][index
]
3045 Trace("strings-loop") << " ... T(Y.Z)= ";
3046 std::vector
<Node
>& veci
= normal_forms
[loop_n_index
];
3047 std::vector
<Node
> vec_t(veci
.begin() + index
, veci
.begin() + loop_index
);
3048 Node t_yz
= mkConcat(vec_t
);
3049 Trace("strings-loop") << " (" << t_yz
<< ")" << std::endl
;
3050 Trace("strings-loop") << " ... S(Z.Y)= ";
3051 std::vector
<Node
>& vecoi
= normal_forms
[other_n_index
];
3052 std::vector
<Node
> vec_s(vecoi
.begin() + index
+ 1, vecoi
.end());
3053 Node s_zy
= mkConcat(vec_s
);
3054 Trace("strings-loop") << s_zy
<< std::endl
;
3055 Trace("strings-loop") << " ... R= ";
3056 std::vector
<Node
> vec_r(veci
.begin() + loop_index
+ 1, veci
.end());
3057 Node r
= mkConcat(vec_r
);
3058 Trace("strings-loop") << r
<< std::endl
;
3060 if (s_zy
.isConst() && r
.isConst() && r
!= d_emptyString
)
3064 if (s_zy
.getConst
<String
>().tailcmp(r
.getConst
<String
>(), c
))
3068 s_zy
= nm
->mkConst(s_zy
.getConst
<String
>().substr(0, c
));
3071 Trace("strings-loop") << "Strings::Loop: Refactor S(Z.Y)= " << s_zy
3072 << ", c=" << c
<< std::endl
;
3078 Trace("strings-loop") << "Strings::Loop: tails are different."
3080 sendInference(info
.d_ant
, conc
, "Loop Conflict", true);
3086 for (unsigned r
= 0; r
< 2; r
++)
3088 Node t
= r
== 0 ? normal_forms
[loop_n_index
][loop_index
] : t_yz
;
3089 split_eq
= t
.eqNode(d_emptyString
);
3090 Node split_eqr
= Rewriter::rewrite(split_eq
);
3091 // the equality could rewrite to false
3092 if (!split_eqr
.isConst())
3094 if (!areDisequal(t
, d_emptyString
))
3096 // try to make t equal to empty to avoid loop
3097 info
.d_conc
= nm
->mkNode(kind::OR
, split_eq
, split_eq
.negate());
3098 info
.d_id
= INFER_LEN_SPLIT_EMP
;
3103 info
.d_ant
.push_back(split_eq
.negate());
3108 Assert(!split_eqr
.getConst
<bool>());
3112 Node ant
= mkExplain(info
.d_ant
);
3114 info
.d_antn
.push_back(ant
);
3117 if (s_zy
== t_yz
&& r
== d_emptyString
&& s_zy
.isConst()
3118 && s_zy
.getConst
<String
>().isRepeated())
3120 Node rep_c
= nm
->mkConst(s_zy
.getConst
<String
>().substr(0, 1));
3121 Trace("strings-loop") << "Special case (X)="
3122 << normal_forms
[other_n_index
][index
] << " "
3124 Trace("strings-loop") << "... (C)=" << rep_c
<< " " << std::endl
;
3127 nm
->mkNode(kind::STRING_IN_REGEXP
,
3128 normal_forms
[other_n_index
][index
],
3129 nm
->mkNode(kind::REGEXP_STAR
,
3130 nm
->mkNode(kind::STRING_TO_REGEXP
, rep_c
)));
3133 else if (t_yz
.isConst())
3135 Trace("strings-loop") << "Strings::Loop: Const Normal Breaking."
3137 CVC4::String s
= t_yz
.getConst
<CVC4::String
>();
3138 unsigned size
= s
.size();
3139 std::vector
<Node
> vconc
;
3140 for (unsigned len
= 1; len
<= size
; len
++)
3142 Node y
= nm
->mkConst(s
.substr(0, len
));
3143 Node z
= nm
->mkConst(s
.substr(len
, size
- len
));
3146 if (r
!= d_emptyString
)
3148 std::vector
<Node
> v2(vec_r
);
3149 v2
.insert(v2
.begin(), y
);
3150 v2
.insert(v2
.begin(), z
);
3151 restr
= mkConcat(z
, y
);
3152 cc
= Rewriter::rewrite(s_zy
.eqNode(mkConcat(v2
)));
3156 cc
= Rewriter::rewrite(s_zy
.eqNode(mkConcat(z
, y
)));
3162 Node conc2
= nm
->mkNode(
3163 kind::STRING_IN_REGEXP
,
3164 normal_forms
[other_n_index
][index
],
3165 nm
->mkNode(kind::REGEXP_CONCAT
,
3166 nm
->mkNode(kind::STRING_TO_REGEXP
, y
),
3167 nm
->mkNode(kind::REGEXP_STAR
,
3168 nm
->mkNode(kind::STRING_TO_REGEXP
, restr
))));
3169 cc
= cc
== d_true
? conc2
: nm
->mkNode(kind::AND
, cc
, conc2
);
3170 d_regexp_ant
[conc2
] = ant
;
3171 vconc
.push_back(cc
);
3173 conc
= vconc
.size() == 0 ? Node::null() : vconc
.size() == 1
3175 : nm
->mkNode(kind::OR
, vconc
);
3179 Trace("strings-loop") << "Strings::Loop: Normal Loop Breaking."
3182 Node sk_w
= mkSkolemS("w_loop");
3183 Node sk_y
= mkSkolemS("y_loop", 1);
3184 Node sk_z
= mkSkolemS("z_loop");
3185 // t1 * ... * tn = y * z
3186 Node conc1
= t_yz
.eqNode(mkConcat(sk_y
, sk_z
));
3187 // s1 * ... * sk = z * y * r
3188 vec_r
.insert(vec_r
.begin(), sk_y
);
3189 vec_r
.insert(vec_r
.begin(), sk_z
);
3190 Node conc2
= s_zy
.eqNode(mkConcat(vec_r
));
3192 normal_forms
[other_n_index
][index
].eqNode(mkConcat(sk_y
, sk_w
));
3193 Node restr
= r
== d_emptyString
? s_zy
: mkConcat(sk_z
, sk_y
);
3195 nm
->mkNode(kind::STRING_IN_REGEXP
,
3197 nm
->mkNode(kind::REGEXP_STAR
,
3198 nm
->mkNode(kind::STRING_TO_REGEXP
, restr
)));
3200 std::vector
<Node
> vec_conc
;
3201 vec_conc
.push_back(conc1
);
3202 vec_conc
.push_back(conc2
);
3203 vec_conc
.push_back(conc3
);
3204 vec_conc
.push_back(str_in_re
);
3205 // vec_conc.push_back(sk_y.eqNode(d_emptyString).negate());//by mkskolems
3206 conc
= nm
->mkNode(kind::AND
, vec_conc
);
3209 // set its antecedant to ant, to say when it is relevant
3210 if (!str_in_re
.isNull())
3212 d_regexp_ant
[str_in_re
] = ant
;
3215 if (options::stringProcessLoop())
3218 info
.d_id
= INFER_FLOOP
;
3219 info
.d_nf_pair
[0] = normal_form_src
[i
];
3220 info
.d_nf_pair
[1] = normal_form_src
[j
];
3223 d_out
->setIncomplete();
3227 //return true for lemma, false if we succeed
3228 void TheoryStrings::processDeq( Node ni
, Node nj
) {
3229 //Assert( areDisequal( ni, nj ) );
3230 if( d_normal_forms
[ni
].size()>1 || d_normal_forms
[nj
].size()>1 ){
3231 std::vector
< Node
> nfi
;
3232 nfi
.insert( nfi
.end(), d_normal_forms
[ni
].begin(), d_normal_forms
[ni
].end() );
3233 std::vector
< Node
> nfj
;
3234 nfj
.insert( nfj
.end(), d_normal_forms
[nj
].begin(), d_normal_forms
[nj
].end() );
3236 int revRet
= processReverseDeq( nfi
, nfj
, ni
, nj
);
3242 nfi
.insert( nfi
.end(), d_normal_forms
[ni
].begin(), d_normal_forms
[ni
].end() );
3244 nfj
.insert( nfj
.end(), d_normal_forms
[nj
].begin(), d_normal_forms
[nj
].end() );
3247 while( index
<nfi
.size() || index
<nfj
.size() ){
3248 int ret
= processSimpleDeq( nfi
, nfj
, ni
, nj
, index
, false );
3252 Assert( index
<nfi
.size() && index
<nfj
.size() );
3253 Node i
= nfi
[index
];
3254 Node j
= nfj
[index
];
3255 Trace("strings-solve-debug") << "...Processing(DEQ) " << i
<< " " << j
<< std::endl
;
3256 if( !areEqual( i
, j
) ){
3257 Assert( i
.getKind()!=kind::CONST_STRING
|| j
.getKind()!=kind::CONST_STRING
);
3258 std::vector
< Node
> lexp
;
3259 Node li
= getLength( i
, lexp
);
3260 Node lj
= getLength( j
, lexp
);
3261 if( areDisequal( li
, lj
) ){
3262 if( i
.getKind()==kind::CONST_STRING
|| j
.getKind()==kind::CONST_STRING
){
3264 Node const_k
= i
.getKind() == kind::CONST_STRING
? i
: j
;
3265 Node nconst_k
= i
.getKind() == kind::CONST_STRING
? j
: i
;
3266 Node lnck
= i
.getKind() == kind::CONST_STRING
? lj
: li
;
3267 if( !d_equalityEngine
.areDisequal( nconst_k
, d_emptyString
, true ) ){
3268 Node eq
= nconst_k
.eqNode( d_emptyString
);
3269 Node conc
= NodeManager::currentNM()->mkNode( kind::OR
, eq
, eq
.negate() );
3270 sendInference( d_empty_vec
, conc
, "D-DISL-Emp-Split" );
3273 //split on first character
3274 CVC4::String str
= const_k
.getConst
<String
>();
3275 Node firstChar
= str
.size() == 1 ? const_k
: NodeManager::currentNM()->mkConst( str
.prefix( 1 ) );
3276 if( areEqual( lnck
, d_one
) ){
3277 if( areDisequal( firstChar
, nconst_k
) ){
3279 }else if( !areEqual( firstChar
, nconst_k
) ){
3280 //splitting on demand : try to make them disequal
3282 firstChar
, nconst_k
, "S-Split(DEQL-Const)", false))
3288 Node sk
= mkSkolemCached( nconst_k
, firstChar
, sk_id_dc_spt
, "dc_spt", 2 );
3289 Node skr
= mkSkolemCached( nconst_k
, firstChar
, sk_id_dc_spt_rem
, "dc_spt_rem" );
3290 Node eq1
= nconst_k
.eqNode( NodeManager::currentNM()->mkNode( kind::STRING_CONCAT
, sk
, skr
) );
3291 eq1
= Rewriter::rewrite( eq1
);
3292 Node eq2
= nconst_k
.eqNode( NodeManager::currentNM()->mkNode( kind::STRING_CONCAT
, firstChar
, skr
) );
3293 std::vector
< Node
> antec
;
3294 antec
.insert( antec
.end(), d_normal_forms_exp
[ni
].begin(), d_normal_forms_exp
[ni
].end() );
3295 antec
.insert( antec
.end(), d_normal_forms_exp
[nj
].begin(), d_normal_forms_exp
[nj
].end() );
3296 antec
.push_back( nconst_k
.eqNode( d_emptyString
).negate() );
3297 sendInference( antec
, NodeManager::currentNM()->mkNode( kind::OR
,
3298 NodeManager::currentNM()->mkNode( kind::AND
, eq1
, sk
.eqNode( firstChar
).negate() ), eq2
), "D-DISL-CSplit" );
3299 d_pending_req_phase
[ eq1
] = true;
3304 Trace("strings-solve") << "Non-Simple Case 1 : add lemma " << std::endl
;
3306 std::vector
< Node
> antec
;
3307 std::vector
< Node
> antec_new_lits
;
3308 antec
.insert( antec
.end(), d_normal_forms_exp
[ni
].begin(), d_normal_forms_exp
[ni
].end() );
3309 antec
.insert( antec
.end(), d_normal_forms_exp
[nj
].begin(), d_normal_forms_exp
[nj
].end() );
3311 if( areDisequal( ni
, nj
) ){
3312 antec
.push_back( ni
.eqNode( nj
).negate() );
3314 antec_new_lits
.push_back( ni
.eqNode( nj
).negate() );
3316 antec_new_lits
.push_back( li
.eqNode( lj
).negate() );
3317 std::vector
< Node
> conc
;
3318 Node sk1
= mkSkolemCached( i
, j
, sk_id_deq_x
, "x_dsplit" );
3319 Node sk2
= mkSkolemCached( i
, j
, sk_id_deq_y
, "y_dsplit" );
3320 Node sk3
= mkSkolemCached( i
, j
, sk_id_deq_z
, "z_dsplit", 1 );
3321 //Node nemp = sk3.eqNode(d_emptyString).negate();
3322 //conc.push_back(nemp);
3323 Node lsk1
= mkLength( sk1
);
3324 conc
.push_back( lsk1
.eqNode( li
) );
3325 Node lsk2
= mkLength( sk2
);
3326 conc
.push_back( lsk2
.eqNode( lj
) );
3327 conc
.push_back( NodeManager::currentNM()->mkNode( kind::OR
, j
.eqNode( mkConcat( sk1
, sk3
) ), i
.eqNode( mkConcat( sk2
, sk3
) ) ) );
3328 sendInference( antec
, antec_new_lits
, NodeManager::currentNM()->mkNode( kind::AND
, conc
), "D-DISL-Split" );
3329 ++(d_statistics
.d_deq_splits
);
3332 }else if( areEqual( li
, lj
) ){
3333 Assert( !areDisequal( i
, j
) );
3334 //splitting on demand : try to make them disequal
3335 if (sendSplit(i
, j
, "S-Split(DEQL)", false))
3340 //splitting on demand : try to make lengths equal
3341 if (sendSplit(li
, lj
, "D-Split"))
3354 int TheoryStrings::processReverseDeq( std::vector
< Node
>& nfi
, std::vector
< Node
>& nfj
, Node ni
, Node nj
) {
3355 //reverse normal form of i, j
3356 std::reverse( nfi
.begin(), nfi
.end() );
3357 std::reverse( nfj
.begin(), nfj
.end() );
3360 int ret
= processSimpleDeq( nfi
, nfj
, ni
, nj
, index
, true );
3362 //reverse normal form of i, j
3363 std::reverse( nfi
.begin(), nfi
.end() );
3364 std::reverse( nfj
.begin(), nfj
.end() );
3369 int TheoryStrings::processSimpleDeq( std::vector
< Node
>& nfi
, std::vector
< Node
>& nfj
, Node ni
, Node nj
, unsigned& index
, bool isRev
){
3370 // See if one side is constant, if so, the disequality ni != nj is satisfied
3371 // since ni does not contain nj or vice versa.
3372 // This is only valid when isRev is false, since when isRev=true, the contents
3373 // of normal form vectors nfi and nfj are reversed.
3376 for (unsigned i
= 0; i
< 2; i
++)
3378 Node c
= getConstantEqc(i
== 0 ? ni
: nj
);
3382 if (!TheoryStringsRewriter::canConstantContainList(
3383 c
, i
== 0 ? nfj
: nfi
, findex
, lindex
))
3385 Trace("strings-solve-debug")
3386 << "Disequality: constant cannot contain list" << std::endl
;
3392 while( index
<nfi
.size() || index
<nfj
.size() ) {
3393 if( index
>=nfi
.size() || index
>=nfj
.size() ){
3394 Trace("strings-solve-debug") << "Disequality normalize empty" << std::endl
;
3395 std::vector
< Node
> ant
;
3396 //we have a conflict : because the lengths are equal, the remainder needs to be empty, which will lead to a conflict
3397 Node lni
= getLengthExp( ni
, ant
, d_normal_forms_base
[ni
] );
3398 Node lnj
= getLengthExp( nj
, ant
, d_normal_forms_base
[nj
] );
3399 ant
.push_back( lni
.eqNode( lnj
) );
3400 ant
.insert( ant
.end(), d_normal_forms_exp
[ni
].begin(), d_normal_forms_exp
[ni
].end() );
3401 ant
.insert( ant
.end(), d_normal_forms_exp
[nj
].begin(), d_normal_forms_exp
[nj
].end() );
3402 std::vector
< Node
> cc
;
3403 std::vector
< Node
>& nfk
= index
>=nfi
.size() ? nfj
: nfi
;
3404 for( unsigned index_k
=index
; index_k
<nfk
.size(); index_k
++ ){
3405 cc
.push_back( nfk
[index_k
].eqNode( d_emptyString
) );
3407 Node conc
= cc
.size()==1 ? cc
[0] : NodeManager::currentNM()->mkNode( kind::AND
, cc
);
3408 conc
= Rewriter::rewrite( conc
);
3409 sendInference( ant
, conc
, "Disequality Normalize Empty", true);
3412 Node i
= nfi
[index
];
3413 Node j
= nfj
[index
];
3414 Trace("strings-solve-debug") << "...Processing(QED) " << i
<< " " << j
<< std::endl
;
3415 if( !areEqual( i
, j
) ) {
3416 if( i
.getKind()==kind::CONST_STRING
&& j
.getKind()==kind::CONST_STRING
) {
3417 unsigned int len_short
= i
.getConst
<String
>().size() < j
.getConst
<String
>().size() ? i
.getConst
<String
>().size() : j
.getConst
<String
>().size();
3418 bool isSameFix
= isRev
? i
.getConst
<String
>().rstrncmp(j
.getConst
<String
>(), len_short
): i
.getConst
<String
>().strncmp(j
.getConst
<String
>(), len_short
);
3420 //same prefix/suffix
3421 //k is the index of the string that is shorter
3422 Node nk
= i
.getConst
<String
>().size() < j
.getConst
<String
>().size() ? i
: j
;
3423 Node nl
= i
.getConst
<String
>().size() < j
.getConst
<String
>().size() ? j
: i
;
3426 int new_len
= nl
.getConst
<String
>().size() - len_short
;
3427 remainderStr
= NodeManager::currentNM()->mkConst( nl
.getConst
<String
>().substr(0, new_len
) );
3428 Trace("strings-solve-debug-test") << "Rev. Break normal form of " << nl
<< " into " << nk
<< ", " << remainderStr
<< std::endl
;
3430 remainderStr
= NodeManager::currentNM()->mkConst( nl
.getConst
<String
>().substr( len_short
) );
3431 Trace("strings-solve-debug-test") << "Break normal form of " << nl
<< " into " << nk
<< ", " << remainderStr
<< std::endl
;
3433 if( i
.getConst
<String
>().size() < j
.getConst
<String
>().size() ) {
3434 nfj
.insert( nfj
.begin() + index
+ 1, remainderStr
);
3435 nfj
[index
] = nfi
[index
];
3437 nfi
.insert( nfi
.begin() + index
+ 1, remainderStr
);
3438 nfi
[index
] = nfj
[index
];
3444 std::vector
< Node
> lexp
;
3445 Node li
= getLength( i
, lexp
);
3446 Node lj
= getLength( j
, lexp
);
3447 if( areEqual( li
, lj
) && areDisequal( i
, j
) ){
3448 Trace("strings-solve") << "Simple Case 2 : found equal length disequal sub strings " << i
<< " " << j
<< std::endl
;
3449 //we are done: D-Remove
3462 void TheoryStrings::addNormalFormPair( Node n1
, Node n2
){
3463 if( !isNormalFormPair( n1
, n2
) ){
3465 NodeIntMap::const_iterator it
= d_nf_pairs
.find( n1
);
3466 if( it
!=d_nf_pairs
.end() ){
3467 index
= (*it
).second
;
3469 d_nf_pairs
[n1
] = index
+ 1;
3470 if( index
<(int)d_nf_pairs_data
[n1
].size() ){
3471 d_nf_pairs_data
[n1
][index
] = n2
;
3473 d_nf_pairs_data
[n1
].push_back( n2
);
3475 Assert( isNormalFormPair( n1
, n2
) );
3477 Trace("strings-nf-debug") << "Already a normal form pair " << n1
<< " " << n2
<< std::endl
;
3481 bool TheoryStrings::isNormalFormPair( Node n1
, Node n2
) {
3482 //TODO: modulo equality?
3483 return isNormalFormPair2( n1
, n2
) || isNormalFormPair2( n2
, n1
);
3486 bool TheoryStrings::isNormalFormPair2( Node n1
, Node n2
) {
3487 //Trace("strings-debug") << "is normal form pair. " << n1 << " " << n2 << std::endl;
3488 NodeIntMap::const_iterator it
= d_nf_pairs
.find( n1
);
3489 if( it
!=d_nf_pairs
.end() ){
3490 Assert( d_nf_pairs_data
.find( n1
)!=d_nf_pairs_data
.end() );
3491 for( int i
=0; i
<(*it
).second
; i
++ ){
3492 Assert( i
<(int)d_nf_pairs_data
[n1
].size() );
3493 if( d_nf_pairs_data
[n1
][i
]==n2
){
3501 void TheoryStrings::registerTerm( Node n
, int effort
) {
3502 TypeNode tn
= n
.getType();
3503 bool do_register
= true;
3506 if (options::stringEagerLen())
3508 do_register
= effort
== 0;
3512 do_register
= effort
> 0 || n
.getKind() != kind::STRING_CONCAT
;
3516 if(d_registered_terms_cache
.find(n
) == d_registered_terms_cache
.end()) {
3517 d_registered_terms_cache
.insert(n
);
3518 Debug("strings-register") << "TheoryStrings::registerTerm() " << n
<< ", effort = " << effort
<< std::endl
;
3521 //register length information:
3522 // for variables, split on empty vs positive length
3523 // for concat/const/replace, introduce proxy var and state length relation
3525 bool processed
= false;
3526 if( n
.getKind()!=kind::STRING_CONCAT
&& n
.getKind()!=kind::CONST_STRING
) {
3527 if( d_length_lemma_terms_cache
.find( n
)==d_length_lemma_terms_cache
.end() ){
3528 Node lsumb
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, n
);
3529 lsum
= Rewriter::rewrite( lsumb
);
3530 // can register length term if it does not rewrite
3532 sendLengthLemma( n
);
3540 Node sk
= mkSkolemS( "lsym", -1 );
3541 StringsProxyVarAttribute spva
;
3542 sk
.setAttribute(spva
,true);
3543 Node eq
= Rewriter::rewrite( sk
.eqNode(n
) );
3544 Trace("strings-lemma") << "Strings::Lemma LENGTH Term : " << eq
<< std::endl
;
3545 d_proxy_var
[n
] = sk
;
3546 Trace("strings-assert") << "(assert " << eq
<< ")" << std::endl
;
3548 Node skl
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, sk
);
3549 if( n
.getKind()==kind::STRING_CONCAT
){
3550 std::vector
<Node
> node_vec
;
3551 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ) {
3552 if( n
[i
].getAttribute(StringsProxyVarAttribute()) ){
3553 Assert( d_proxy_var_to_length
.find( n
[i
] )!=d_proxy_var_to_length
.end() );
3554 node_vec
.push_back( d_proxy_var_to_length
[n
[i
]] );
3556 Node lni
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, n
[i
] );
3557 node_vec
.push_back(lni
);
3560 lsum
= NodeManager::currentNM()->mkNode( kind::PLUS
, node_vec
);
3561 lsum
= Rewriter::rewrite( lsum
);
3562 }else if( n
.getKind()==kind::CONST_STRING
){
3563 lsum
= NodeManager::currentNM()->mkConst( ::CVC4::Rational( n
.getConst
<String
>().size() ) );
3565 Assert( !lsum
.isNull() );
3566 d_proxy_var_to_length
[sk
] = lsum
;
3567 Node ceq
= Rewriter::rewrite( skl
.eqNode( lsum
) );
3568 Trace("strings-lemma") << "Strings::Lemma LENGTH : " << ceq
<< std::endl
;
3569 Trace("strings-lemma-debug") << " prerewrite : " << skl
.eqNode( lsum
) << std::endl
;
3570 Trace("strings-assert") << "(assert " << ceq
<< ")" << std::endl
;
3574 else if (n
.getKind() == kind::STRING_CODE
)
3576 d_has_str_code
= true;
3577 NodeManager
* nm
= NodeManager::currentNM();
3578 // ite( str.len(s)==1, 0 <= str.code(s) < num_codes, str.code(s)=-1 )
3579 Node code_len
= mkLength(n
[0]).eqNode(d_one
);
3580 Node code_eq_neg1
= n
.eqNode(d_neg_one
);
3581 Node code_range
= nm
->mkNode(
3583 nm
->mkNode(kind::GEQ
, n
, d_zero
),
3585 kind::LT
, n
, nm
->mkConst(Rational(CVC4::String::num_codes()))));
3586 Node lem
= nm
->mkNode(kind::ITE
, code_len
, code_range
, code_eq_neg1
);
3587 Trace("strings-lemma") << "Strings::Lemma CODE : " << lem
<< std::endl
;
3588 Trace("strings-assert") << "(assert " << lem
<< ")" << std::endl
;
3595 void TheoryStrings::sendInference( std::vector
< Node
>& exp
, std::vector
< Node
>& exp_n
, Node eq
, const char * c
, bool asLemma
) {
3596 eq
= eq
.isNull() ? d_false
: Rewriter::rewrite( eq
);
3598 if( Trace
.isOn("strings-infer-debug") ){
3599 Trace("strings-infer-debug") << "By " << c
<< ", infer : " << eq
<< " from: " << std::endl
;
3600 for( unsigned i
=0; i
<exp
.size(); i
++ ){
3601 Trace("strings-infer-debug") << " " << exp
[i
] << std::endl
;
3603 for( unsigned i
=0; i
<exp_n
.size(); i
++ ){
3604 Trace("strings-infer-debug") << " N:" << exp_n
[i
] << std::endl
;
3606 //Trace("strings-infer-debug") << "as lemma : " << asLemma << std::endl;
3608 //check if we should send a lemma or an inference
3609 if( asLemma
|| eq
==d_false
|| eq
.getKind()==kind::OR
|| !exp_n
.empty() || options::stringInferAsLemmas() ){
3611 if( options::stringRExplainLemmas() ){
3612 eq_exp
= mkExplain( exp
, exp_n
);
3615 eq_exp
= mkAnd( exp_n
);
3616 }else if( exp_n
.empty() ){
3617 eq_exp
= mkAnd( exp
);
3619 std::vector
< Node
> ev
;
3620 ev
.insert( ev
.end(), exp
.begin(), exp
.end() );
3621 ev
.insert( ev
.end(), exp_n
.begin(), exp_n
.end() );
3622 eq_exp
= NodeManager::currentNM()->mkNode( kind::AND
, ev
);
3625 // if we have unexplained literals, this lemma is not a conflict
3626 if (eq
== d_false
&& !exp_n
.empty())
3628 eq
= eq_exp
.negate();
3631 sendLemma( eq_exp
, eq
, c
);
3633 sendInfer( mkAnd( exp
), eq
, c
);
3638 void TheoryStrings::sendInference( std::vector
< Node
>& exp
, Node eq
, const char * c
, bool asLemma
) {
3639 std::vector
< Node
> exp_n
;
3640 sendInference( exp
, exp_n
, eq
, c
, asLemma
);
3643 void TheoryStrings::sendLemma( Node ant
, Node conc
, const char * c
) {
3644 if( conc
.isNull() || conc
== d_false
) {
3645 Trace("strings-conflict") << "Strings::Conflict : " << c
<< " : " << ant
<< std::endl
;
3646 Trace("strings-lemma") << "Strings::Conflict : " << c
<< " : " << ant
<< std::endl
;
3647 Trace("strings-assert") << "(assert (not " << ant
<< ")) ; conflict " << c
<< std::endl
;
3648 d_out
->conflict(ant
);
3652 if( ant
== d_true
) {
3655 lem
= NodeManager::currentNM()->mkNode( kind::IMPLIES
, ant
, conc
);
3657 Trace("strings-lemma") << "Strings::Lemma " << c
<< " : " << lem
<< std::endl
;
3658 Trace("strings-assert") << "(assert " << lem
<< ") ; lemma " << c
<< std::endl
;
3659 d_lemma_cache
.push_back( lem
);
3663 void TheoryStrings::sendInfer( Node eq_exp
, Node eq
, const char * c
) {
3664 if( options::stringInferSym() ){
3665 std::vector
< Node
> vars
;
3666 std::vector
< Node
> subs
;
3667 std::vector
< Node
> unproc
;
3668 inferSubstitutionProxyVars( eq_exp
, vars
, subs
, unproc
);
3669 if( unproc
.empty() ){
3670 Trace("strings-lemma-debug") << "Strings::Infer " << eq
<< " from " << eq_exp
<< " by " << c
<< std::endl
;
3671 Node eqs
= eq
.substitute( vars
.begin(), vars
.end(), subs
.begin(), subs
.end() );
3672 Trace("strings-lemma-debug") << "Strings::Infer Alternate : " << eqs
<< std::endl
;
3673 for( unsigned i
=0; i
<vars
.size(); i
++ ){
3674 Trace("strings-lemma-debug") << " " << vars
[i
] << " -> " << subs
[i
] << std::endl
;
3676 sendLemma( d_true
, eqs
, c
);
3679 for( unsigned i
=0; i
<unproc
.size(); i
++ ){
3680 Trace("strings-lemma-debug") << " non-trivial exp : " << unproc
[i
] << std::endl
;
3684 Trace("strings-lemma") << "Strings::Infer " << eq
<< " from " << eq_exp
<< " by " << c
<< std::endl
;
3685 Trace("strings-assert") << "(assert (=> " << eq_exp
<< " " << eq
<< ")) ; infer " << c
<< std::endl
;
3686 d_pending
.push_back( eq
);
3687 d_pending_exp
[eq
] = eq_exp
;
3688 d_infer
.push_back( eq
);
3689 d_infer_exp
.push_back( eq_exp
);
3692 bool TheoryStrings::sendSplit(Node a
, Node b
, const char* c
, bool preq
)
3694 Node eq
= a
.eqNode( b
);
3695 eq
= Rewriter::rewrite( eq
);
3698 Node neq
= NodeManager::currentNM()->mkNode(kind::NOT
, eq
);
3699 Node lemma_or
= NodeManager::currentNM()->mkNode(kind::OR
, eq
, neq
);
3700 Trace("strings-lemma") << "Strings::Lemma " << c
<< " SPLIT : " << lemma_or
3702 d_lemma_cache
.push_back(lemma_or
);
3703 d_pending_req_phase
[eq
] = preq
;
3704 ++(d_statistics
.d_splits
);
3711 void TheoryStrings::sendLengthLemma( Node n
){
3712 Node n_len
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, n
);
3713 if( options::stringSplitEmp() || !options::stringLenGeqZ() ){
3714 NodeManager
* nm
= NodeManager::currentNM();
3715 Node n_len_eq_z
= n_len
.eqNode( d_zero
);
3716 Node n_len_eq_z_2
= n
.eqNode( d_emptyString
);
3717 Node case_empty
= nm
->mkNode(AND
, n_len_eq_z
, n_len_eq_z_2
);
3718 case_empty
= Rewriter::rewrite(case_empty
);
3719 Node case_nempty
= nm
->mkNode(GT
, n_len
, d_zero
);
3720 if (!case_empty
.isConst())
3722 Node lem
= nm
->mkNode(OR
, case_empty
, case_nempty
);
3724 Trace("strings-lemma") << "Strings::Lemma LENGTH >= 0 : " << lem
3726 // prefer trying the empty case first
3727 // notice that requirePhase must only be called on rewritten literals that
3728 // occur in the CNF stream.
3729 n_len_eq_z
= Rewriter::rewrite(n_len_eq_z
);
3730 Assert(!n_len_eq_z
.isConst());
3731 d_out
->requirePhase(n_len_eq_z
, true);
3732 n_len_eq_z_2
= Rewriter::rewrite(n_len_eq_z_2
);
3733 Assert(!n_len_eq_z_2
.isConst());
3734 d_out
->requirePhase(n_len_eq_z_2
, true);
3736 else if (!case_empty
.getConst
<bool>())
3738 // the rewriter knows that n is non-empty
3739 Trace("strings-lemma")
3740 << "Strings::Lemma LENGTH > 0 (non-empty): " << case_nempty
3742 d_out
->lemma(case_nempty
);
3746 // If n = "" ---> true or len( n ) = 0 ----> true, then we expect that
3747 // n ---> "". Since this method is only called on non-constants n, it must
3748 // be that n = "" ^ len( n ) = 0 does not rewrite to true.
3752 //AJR: probably a good idea
3753 if( options::stringLenGeqZ() ){
3754 Node n_len_geq
= NodeManager::currentNM()->mkNode( kind::GEQ
, n_len
, d_zero
);
3755 n_len_geq
= Rewriter::rewrite( n_len_geq
);
3756 d_out
->lemma( n_len_geq
);
3760 void TheoryStrings::inferSubstitutionProxyVars( Node n
, std::vector
< Node
>& vars
, std::vector
< Node
>& subs
, std::vector
< Node
>& unproc
) {
3761 if( n
.getKind()==kind::AND
){
3762 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ){
3763 inferSubstitutionProxyVars( n
[i
], vars
, subs
, unproc
);
3766 }else if( n
.getKind()==kind::EQUAL
){
3767 Node ns
= n
.substitute( vars
.begin(), vars
.end(), subs
.begin(), subs
.end() );
3768 ns
= Rewriter::rewrite( ns
);
3769 if( ns
.getKind()==kind::EQUAL
){
3772 for( unsigned i
=0; i
<2; i
++ ){
3774 if( ns
[i
].getAttribute(StringsProxyVarAttribute()) ){
3776 }else if( ns
[i
].isConst() ){
3777 NodeNodeMap::const_iterator it
= d_proxy_var
.find( ns
[i
] );
3778 if( it
!=d_proxy_var
.end() ){
3784 if( v
.getNumChildren()==0 ){
3788 //both sides involved in proxy var
3799 subs
.push_back( s
);
3800 vars
.push_back( v
);
3808 unproc
.push_back( n
);
3813 Node
TheoryStrings::mkConcat( Node n1
, Node n2
) {
3814 return Rewriter::rewrite( NodeManager::currentNM()->mkNode( kind::STRING_CONCAT
, n1
, n2
) );
3817 Node
TheoryStrings::mkConcat( Node n1
, Node n2
, Node n3
) {
3818 return Rewriter::rewrite( NodeManager::currentNM()->mkNode( kind::STRING_CONCAT
, n1
, n2
, n3
) );
3821 Node
TheoryStrings::mkConcat( const std::vector
< Node
>& c
) {
3822 return Rewriter::rewrite( c
.size()>1 ? NodeManager::currentNM()->mkNode( kind::STRING_CONCAT
, c
) : ( c
.size()==1 ? c
[0] : d_emptyString
) );
3825 Node
TheoryStrings::mkLength( Node t
) {
3826 return Rewriter::rewrite( NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, t
) );
3829 Node
TheoryStrings::mkSkolemCached( Node a
, Node b
, int id
, const char * c
, int isLenSplit
){
3830 //return mkSkolemS( c, isLenSplit );
3831 std::map
< int, Node
>::iterator it
= d_skolem_cache
[a
][b
].find( id
);
3832 if( it
==d_skolem_cache
[a
][b
].end() ){
3833 Node sk
= mkSkolemS( c
, isLenSplit
);
3834 d_skolem_cache
[a
][b
][id
] = sk
;
3841 //isLenSplit: -1-ignore, 0-no restriction, 1-greater than one, 2-one
3842 Node
TheoryStrings::mkSkolemS( const char *c
, int isLenSplit
) {
3843 Node n
= NodeManager::currentNM()->mkSkolem( c
, NodeManager::currentNM()->stringType(), "string sko" );
3844 d_all_skolems
.insert(n
);
3845 d_length_lemma_terms_cache
.insert( n
);
3846 ++(d_statistics
.d_new_skolems
);
3847 if( isLenSplit
==0 ){
3848 sendLengthLemma( n
);
3849 } else if( isLenSplit
== 1 ){
3850 registerNonEmptySkolem( n
);
3851 }else if( isLenSplit
==2 ){
3852 Node len_one
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, n
).eqNode( d_one
);
3853 Trace("strings-lemma") << "Strings::Lemma SK-ONE : " << len_one
<< std::endl
;
3854 Trace("strings-assert") << "(assert " << len_one
<< ")" << std::endl
;
3855 d_out
->lemma( len_one
);
3860 void TheoryStrings::registerNonEmptySkolem( Node n
) {
3861 if( d_skolem_ne_reg_cache
.find( n
)==d_skolem_ne_reg_cache
.end() ){
3862 d_skolem_ne_reg_cache
.insert( n
);
3863 d_equalityEngine
.assertEquality(n
.eqNode(d_emptyString
), false, d_true
);
3864 Node len_n_gt_z
= NodeManager::currentNM()->mkNode(kind::GT
,
3865 NodeManager::currentNM()->mkNode(kind::STRING_LENGTH
, n
), d_zero
);
3866 Trace("strings-lemma") << "Strings::Lemma SK-NON-ZERO : " << len_n_gt_z
<< std::endl
;
3867 Trace("strings-assert") << "(assert " << len_n_gt_z
<< ")" << std::endl
;
3868 d_out
->lemma(len_n_gt_z
);
3872 Node
TheoryStrings::mkExplain( std::vector
< Node
>& a
) {
3873 std::vector
< Node
> an
;
3874 return mkExplain( a
, an
);
3877 Node
TheoryStrings::mkExplain( std::vector
< Node
>& a
, std::vector
< Node
>& an
) {
3878 std::vector
< TNode
> antec_exp
;
3879 for( unsigned i
=0; i
<a
.size(); i
++ ) {
3880 if( std::find( a
.begin(), a
.begin() + i
, a
[i
] )==a
.begin() + i
) {
3882 Debug("strings-explain") << "Ask for explanation of " << a
[i
] << std::endl
;
3884 if(a
[i
].getKind() == kind::EQUAL
) {
3885 //Assert( hasTerm(a[i][0]) );
3886 //Assert( hasTerm(a[i][1]) );
3887 Assert( areEqual(a
[i
][0], a
[i
][1]) );
3888 if( a
[i
][0]==a
[i
][1] ){
3891 } else if( a
[i
].getKind()==kind::NOT
&& a
[i
][0].getKind()==kind::EQUAL
) {
3892 Assert( hasTerm(a
[i
][0][0]) );
3893 Assert( hasTerm(a
[i
][0][1]) );
3894 AlwaysAssert( d_equalityEngine
.areDisequal(a
[i
][0][0], a
[i
][0][1], true) );
3895 }else if( a
[i
].getKind() == kind::AND
){
3896 for( unsigned j
=0; j
<a
[i
].getNumChildren(); j
++ ){
3897 a
.push_back( a
[i
][j
] );
3902 unsigned ps
= antec_exp
.size();
3903 explain(a
[i
], antec_exp
);
3904 Debug("strings-explain") << "Done, explanation was : " << std::endl
;
3905 for( unsigned j
=ps
; j
<antec_exp
.size(); j
++ ) {
3906 Debug("strings-explain") << " " << antec_exp
[j
] << std::endl
;
3908 Debug("strings-explain") << std::endl
;
3912 for( unsigned i
=0; i
<an
.size(); i
++ ) {
3913 if( std::find( an
.begin(), an
.begin() + i
, an
[i
] )==an
.begin() + i
){
3914 Debug("strings-explain") << "Add to explanation (new literal) " << an
[i
] << std::endl
;
3915 antec_exp
.push_back(an
[i
]);
3919 if( antec_exp
.empty() ) {
3921 } else if( antec_exp
.size()==1 ) {
3924 ant
= NodeManager::currentNM()->mkNode( kind::AND
, antec_exp
);
3926 //ant = Rewriter::rewrite( ant );
3930 Node
TheoryStrings::mkAnd( std::vector
< Node
>& a
) {
3931 std::vector
< Node
> au
;
3932 for( unsigned i
=0; i
<a
.size(); i
++ ){
3933 if( std::find( au
.begin(), au
.end(), a
[i
] )==au
.end() ){
3934 au
.push_back( a
[i
] );
3939 } else if( au
.size() == 1 ) {
3942 return NodeManager::currentNM()->mkNode( kind::AND
, au
);
3946 void TheoryStrings::getConcatVec( Node n
, std::vector
< Node
>& c
) {
3947 if( n
.getKind()==kind::STRING_CONCAT
) {
3948 for( unsigned i
=0; i
<n
.getNumChildren(); i
++ ) {
3949 if( !areEqual( n
[i
], d_emptyString
) ) {
3950 c
.push_back( n
[i
] );
3958 void TheoryStrings::checkNormalFormsDeq()
3960 std::vector
< std::vector
< Node
> > cols
;
3961 std::vector
< Node
> lts
;
3962 std::map
< Node
, std::map
< Node
, bool > > processed
;
3964 //for each pair of disequal strings, must determine whether their lengths are equal or disequal
3965 for( NodeList::const_iterator id
= d_ee_disequalities
.begin(); id
!= d_ee_disequalities
.end(); ++id
) {
3968 for( unsigned i
=0; i
<2; i
++ ){
3969 n
[i
] = d_equalityEngine
.getRepresentative( eq
[i
] );
3971 if( processed
[n
[0]].find( n
[1] )==processed
[n
[0]].end() ){
3972 processed
[n
[0]][n
[1]] = true;
3974 for( unsigned i
=0; i
<2; i
++ ){
3975 EqcInfo
* ei
= getOrMakeEqcInfo( n
[i
], false );
3976 lt
[i
] = ei
? ei
->d_length_term
: Node::null();
3977 if( lt
[i
].isNull() ){
3980 lt
[i
] = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, lt
[i
] );
3982 if( !areEqual( lt
[0], lt
[1] ) && !areDisequal( lt
[0], lt
[1] ) ){
3983 sendSplit( lt
[0], lt
[1], "DEQ-LENGTH-SP" );
3988 if( !hasProcessed() ){
3989 separateByLength( d_strings_eqc
, cols
, lts
);
3990 for( unsigned i
=0; i
<cols
.size(); i
++ ){
3991 if( cols
[i
].size()>1 && d_lemma_cache
.empty() ){
3992 Trace("strings-solve") << "- Verify disequalities are processed for " << cols
[i
][0] << ", normal form : ";
3993 printConcat( d_normal_forms
[cols
[i
][0]], "strings-solve" );
3994 Trace("strings-solve") << "... #eql = " << cols
[i
].size() << std::endl
;
3995 //must ensure that normal forms are disequal
3996 for( unsigned j
=0; j
<cols
[i
].size(); j
++ ){
3997 for( unsigned k
=(j
+1); k
<cols
[i
].size(); k
++ ){
3998 //for strings that are disequal, but have the same length
3999 if( areDisequal( cols
[i
][j
], cols
[i
][k
] ) ){
4000 Assert( !d_conflict
);
4001 Trace("strings-solve") << "- Compare " << cols
[i
][j
] << " ";
4002 printConcat( d_normal_forms
[cols
[i
][j
]], "strings-solve" );
4003 Trace("strings-solve") << " against " << cols
[i
][k
] << " ";
4004 printConcat( d_normal_forms
[cols
[i
][k
]], "strings-solve" );
4005 Trace("strings-solve") << "..." << std::endl
;
4006 processDeq( cols
[i
][j
], cols
[i
][k
] );
4007 if( hasProcessed() ){
4018 void TheoryStrings::checkLengthsEqc() {
4019 if( options::stringLenNorm() ){
4020 for( unsigned i
=0; i
<d_strings_eqc
.size(); i
++ ){
4021 //if( d_normal_forms[nodes[i]].size()>1 ) {
4022 Trace("strings-process-debug") << "Process length constraints for " << d_strings_eqc
[i
] << std::endl
;
4023 //check if there is a length term for this equivalence class
4024 EqcInfo
* ei
= getOrMakeEqcInfo( d_strings_eqc
[i
], false );
4025 Node lt
= ei
? ei
->d_length_term
: Node::null();
4026 if( !lt
.isNull() ) {
4027 Node llt
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, lt
);
4028 //now, check if length normalization has occurred
4029 if( ei
->d_normalized_length
.get().isNull() ) {
4030 Node nf
= mkConcat( d_normal_forms
[d_strings_eqc
[i
]] );
4031 if( Trace
.isOn("strings-process-debug") ){
4032 Trace("strings-process-debug") << " normal form is " << nf
<< " from base " << d_normal_forms_base
[d_strings_eqc
[i
]] << std::endl
;
4033 Trace("strings-process-debug") << " normal form exp is: " << std::endl
;
4034 for( unsigned j
=0; j
<d_normal_forms_exp
[d_strings_eqc
[i
]].size(); j
++ ){
4035 Trace("strings-process-debug") << " " << d_normal_forms_exp
[d_strings_eqc
[i
]][j
] << std::endl
;
4039 //if not, add the lemma
4040 std::vector
< Node
> ant
;
4041 ant
.insert( ant
.end(), d_normal_forms_exp
[d_strings_eqc
[i
]].begin(), d_normal_forms_exp
[d_strings_eqc
[i
]].end() );
4042 ant
.push_back( d_normal_forms_base
[d_strings_eqc
[i
]].eqNode( lt
) );
4043 Node lc
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, nf
);
4044 Node lcr
= Rewriter::rewrite( lc
);
4045 Trace("strings-process-debug") << "Rewrote length " << lc
<< " to " << lcr
<< std::endl
;
4046 Node eq
= llt
.eqNode( lcr
);
4048 ei
->d_normalized_length
.set( eq
);
4049 sendInference( ant
, eq
, "LEN-NORM", true );
4053 Trace("strings-process-debug") << "No length term for eqc " << d_strings_eqc
[i
] << " " << d_eqc_to_len_term
[d_strings_eqc
[i
]] << std::endl
;
4054 if( !options::stringEagerLen() ){
4055 Node c
= mkConcat( d_normal_forms
[d_strings_eqc
[i
]] );
4056 registerTerm( c
, 3 );
4059 NodeNodeMap::const_iterator it = d_proxy_var.find( c );
4060 if( it!=d_proxy_var.end() ){
4061 Node pv = (*it).second;
4062 Assert( d_proxy_var_to_length.find( pv )!=d_proxy_var_to_length.end() );
4063 Node pvl = d_proxy_var_to_length[pv];
4064 Node ceq = Rewriter::rewrite( mkLength( pv ).eqNode( pvl ) );
4065 sendInference( d_empty_vec, ceq, "LEN-NORM-I", true );
4072 // Trace("strings-process-debug") << "Do not process length constraints for " << nodes[i] << " " << d_normal_forms[nodes[i]].size() << std::endl;
4078 void TheoryStrings::checkCardinality() {
4079 //int cardinality = options::stringCharCardinality();
4080 //Trace("strings-solve-debug2") << "get cardinality: " << cardinality << endl;
4082 //AJR: this will create a partition of eqc, where each collection has length that are pairwise propagated to be equal.
4083 // we do not require disequalities between the lengths of each collection, since we split on disequalities between lengths of string terms that are disequal (DEQ-LENGTH-SP).
4084 // TODO: revisit this?
4085 std::vector
< std::vector
< Node
> > cols
;
4086 std::vector
< Node
> lts
;
4087 separateByLength( d_strings_eqc
, cols
, lts
);
4089 for( unsigned i
= 0; i
<cols
.size(); ++i
) {
4091 Trace("strings-card") << "Number of strings with length equal to " << lr
<< " is " << cols
[i
].size() << std::endl
;
4092 if( cols
[i
].size() > 1 ) {
4094 unsigned card_need
= 1;
4095 double curr
= (double)cols
[i
].size();
4096 while( curr
>d_card_size
){
4097 curr
= curr
/(double)d_card_size
;
4100 Trace("strings-card") << "Need length " << card_need
<< " for this number of strings (where alphabet size is " << d_card_size
<< ")." << std::endl
;
4101 //check if we need to split
4102 bool needsSplit
= true;
4104 // if constant, compare
4105 Node cmp
= NodeManager::currentNM()->mkNode( kind::GEQ
, lr
, NodeManager::currentNM()->mkConst( Rational( card_need
) ) );
4106 cmp
= Rewriter::rewrite( cmp
);
4107 needsSplit
= cmp
!=d_true
;
4109 // find the minimimum constant that we are unknown to be disequal from, or otherwise stop if we increment such that cardinality does not apply
4111 bool success
= true;
4112 while( r
<card_need
&& success
){
4113 Node rr
= NodeManager::currentNM()->mkConst
<Rational
>( Rational(r
) );
4114 if( areDisequal( rr
, lr
) ){
4121 Trace("strings-card") << "Symbolic length " << lr
<< " must be at least " << r
<< " due to constant disequalities." << std::endl
;
4123 needsSplit
= r
<card_need
;
4127 unsigned int int_k
= (unsigned int)card_need
;
4128 for( std::vector
< Node
>::iterator itr1
= cols
[i
].begin();
4129 itr1
!= cols
[i
].end(); ++itr1
) {
4130 for( std::vector
< Node
>::iterator itr2
= itr1
+ 1;
4131 itr2
!= cols
[i
].end(); ++itr2
) {
4132 if(!areDisequal( *itr1
, *itr2
)) {
4134 if (sendSplit(*itr1
, *itr2
, "CARD-SP"))
4141 EqcInfo
* ei
= getOrMakeEqcInfo( lr
, true );
4142 Trace("strings-card") << "Previous cardinality used for " << lr
<< " is " << ((int)ei
->d_cardinality_lem_k
.get()-1) << std::endl
;
4143 if( int_k
+1 > ei
->d_cardinality_lem_k
.get() ){
4144 Node k_node
= NodeManager::currentNM()->mkConst( ::CVC4::Rational( int_k
) );
4145 //add cardinality lemma
4146 Node dist
= NodeManager::currentNM()->mkNode( kind::DISTINCT
, cols
[i
] );
4147 std::vector
< Node
> vec_node
;
4148 vec_node
.push_back( dist
);
4149 for( std::vector
< Node
>::iterator itr1
= cols
[i
].begin();
4150 itr1
!= cols
[i
].end(); ++itr1
) {
4151 Node len
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, *itr1
);
4153 Node len_eq_lr
= len
.eqNode(lr
);
4154 vec_node
.push_back( len_eq_lr
);
4157 Node len
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, cols
[i
][0] );
4158 Node cons
= NodeManager::currentNM()->mkNode( kind::GEQ
, len
, k_node
);
4159 cons
= Rewriter::rewrite( cons
);
4160 ei
->d_cardinality_lem_k
.set( int_k
+1 );
4162 sendInference( d_empty_vec
, vec_node
, cons
, "CARDINALITY", true );
4171 void TheoryStrings::getEquivalenceClasses( std::vector
< Node
>& eqcs
) {
4172 eq::EqClassesIterator eqcs_i
= eq::EqClassesIterator( &d_equalityEngine
);
4173 while( !eqcs_i
.isFinished() ) {
4174 Node eqc
= (*eqcs_i
);
4175 //if eqc.getType is string
4176 if (eqc
.getType().isString()) {
4177 eqcs
.push_back( eqc
);
4183 void TheoryStrings::separateByLength(std::vector
< Node
>& n
,
4184 std::vector
< std::vector
< Node
> >& cols
,
4185 std::vector
< Node
>& lts
) {
4186 unsigned leqc_counter
= 0;
4187 std::map
< Node
, unsigned > eqc_to_leqc
;
4188 std::map
< unsigned, Node
> leqc_to_eqc
;
4189 std::map
< unsigned, std::vector
< Node
> > eqc_to_strings
;
4190 for( unsigned i
=0; i
<n
.size(); i
++ ) {
4192 Assert( d_equalityEngine
.getRepresentative(eqc
)==eqc
);
4193 EqcInfo
* ei
= getOrMakeEqcInfo( eqc
, false );
4194 Node lt
= ei
? ei
->d_length_term
: Node::null();
4196 lt
= NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, lt
);
4197 Node r
= d_equalityEngine
.getRepresentative( lt
);
4198 if( eqc_to_leqc
.find( r
)==eqc_to_leqc
.end() ){
4199 eqc_to_leqc
[r
] = leqc_counter
;
4200 leqc_to_eqc
[leqc_counter
] = r
;
4203 eqc_to_strings
[ eqc_to_leqc
[r
] ].push_back( eqc
);
4205 eqc_to_strings
[leqc_counter
].push_back( eqc
);
4209 for( std::map
< unsigned, std::vector
< Node
> >::iterator it
= eqc_to_strings
.begin(); it
!= eqc_to_strings
.end(); ++it
){
4210 cols
.push_back( std::vector
< Node
>() );
4211 cols
.back().insert( cols
.back().end(), it
->second
.begin(), it
->second
.end() );
4212 lts
.push_back( leqc_to_eqc
[it
->first
] );
4216 void TheoryStrings::printConcat( std::vector
< Node
>& n
, const char * c
) {
4217 for( unsigned i
=0; i
<n
.size(); i
++ ){
4218 if( i
>0 ) Trace(c
) << " ++ ";
4225 //// Finite Model Finding
4227 Node
TheoryStrings::getNextDecisionRequest( unsigned& priority
) {
4228 if( options::stringFMF() && !d_conflict
){
4229 Node in_var_lsum
= d_input_var_lsum
.get();
4230 //Trace("strings-fmf-debug") << "Strings::FMF: Assertion Level = " << d_valuation.getAssertionLevel() << std::endl;
4231 //initialize the term we will minimize
4232 if( in_var_lsum
.isNull() && !d_input_vars
.empty() ){
4233 Trace("strings-fmf-debug") << "Input variables: ";
4234 std::vector
< Node
> ll
;
4235 for(NodeSet::key_iterator itr
= d_input_vars
.key_begin();
4236 itr
!= d_input_vars
.key_end(); ++itr
) {
4237 Trace("strings-fmf-debug") << " " << (*itr
) ;
4238 ll
.push_back( NodeManager::currentNM()->mkNode( kind::STRING_LENGTH
, *itr
) );
4240 Trace("strings-fmf-debug") << std::endl
;
4241 in_var_lsum
= ll
.size()==1 ? ll
[0] : NodeManager::currentNM()->mkNode( kind::PLUS
, ll
);
4242 in_var_lsum
= Rewriter::rewrite( in_var_lsum
);
4243 d_input_var_lsum
.set( in_var_lsum
);
4245 if( !in_var_lsum
.isNull() ){
4246 //Trace("strings-fmf") << "Get next decision request." << std::endl;
4247 //check if we need to decide on something
4248 int decideCard
= d_curr_cardinality
.get();
4249 if( d_cardinality_lits
.find( decideCard
)!=d_cardinality_lits
.end() ){
4251 Node cnode
= d_cardinality_lits
[ d_curr_cardinality
.get() ];
4252 if( d_valuation
.hasSatValue( cnode
, value
) ) {
4254 d_curr_cardinality
.set( d_curr_cardinality
.get() + 1 );
4255 decideCard
= d_curr_cardinality
.get();
4256 Trace("strings-fmf-debug") << "Has false SAT value, increment and decide." << std::endl
;
4259 Trace("strings-fmf-debug") << "Has true SAT value, do not decide." << std::endl
;
4262 Trace("strings-fmf-debug") << "No SAT value, decide." << std::endl
;
4265 if( decideCard
!=-1 ){
4266 if( d_cardinality_lits
.find( decideCard
)==d_cardinality_lits
.end() ){
4267 Node lit
= NodeManager::currentNM()->mkNode( kind::LEQ
, in_var_lsum
, NodeManager::currentNM()->mkConst( Rational( decideCard
) ) );
4268 lit
= Rewriter::rewrite( lit
);
4269 d_cardinality_lits
[decideCard
] = lit
;
4270 Node lem
= NodeManager::currentNM()->mkNode( kind::OR
, lit
, lit
.negate() );
4271 Trace("strings-fmf") << "Strings::FMF: Add decision lemma " << lem
<< ", decideCard = " << decideCard
<< std::endl
;
4272 d_out
->lemma( lem
);
4273 d_out
->requirePhase( lit
, true );
4275 Node lit
= d_cardinality_lits
[ decideCard
];
4276 Trace("strings-fmf") << "Strings::FMF: Decide positive on " << lit
<< std::endl
;
4282 return Node::null();
4285 Node
TheoryStrings::ppRewrite(TNode atom
) {
4286 Trace("strings-ppr") << "TheoryStrings::ppRewrite " << atom
<< std::endl
;
4287 if( !options::stringLazyPreproc() ){
4288 //eager preprocess here
4289 std::vector
< Node
> new_nodes
;
4290 Node ret
= d_preproc
.processAssertion( atom
, new_nodes
);
4292 Trace("strings-ppr") << " rewrote " << atom
<< " -> " << ret
<< ", with " << new_nodes
.size() << " lemmas." << std::endl
;
4293 for( unsigned i
=0; i
<new_nodes
.size(); i
++ ){
4294 Trace("strings-ppr") << " lemma : " << new_nodes
[i
] << std::endl
;
4295 d_out
->lemma( new_nodes
[i
] );
4299 Assert( new_nodes
.empty() );
4306 TheoryStrings::Statistics::Statistics():
4307 d_splits("theory::strings::NumOfSplitOnDemands", 0),
4308 d_eq_splits("theory::strings::NumOfEqSplits", 0),
4309 d_deq_splits("theory::strings::NumOfDiseqSplits", 0),
4310 d_loop_lemmas("theory::strings::NumOfLoops", 0),
4311 d_new_skolems("theory::strings::NumOfNewSkolems", 0)
4313 smtStatisticsRegistry()->registerStat(&d_splits
);
4314 smtStatisticsRegistry()->registerStat(&d_eq_splits
);
4315 smtStatisticsRegistry()->registerStat(&d_deq_splits
);
4316 smtStatisticsRegistry()->registerStat(&d_loop_lemmas
);
4317 smtStatisticsRegistry()->registerStat(&d_new_skolems
);
4320 TheoryStrings::Statistics::~Statistics(){
4321 smtStatisticsRegistry()->unregisterStat(&d_splits
);
4322 smtStatisticsRegistry()->unregisterStat(&d_eq_splits
);
4323 smtStatisticsRegistry()->unregisterStat(&d_deq_splits
);
4324 smtStatisticsRegistry()->unregisterStat(&d_loop_lemmas
);
4325 smtStatisticsRegistry()->unregisterStat(&d_new_skolems
);
4347 //// Regular Expressions
4350 unsigned TheoryStrings::getNumMemberships( Node n
, bool isPos
) {
4352 NodeIntMap::const_iterator it
= d_pos_memberships
.find( n
);
4353 if( it
!=d_pos_memberships
.end() ){
4354 return (*it
).second
;
4357 NodeIntMap::const_iterator it
= d_neg_memberships
.find( n
);
4358 if( it
!=d_neg_memberships
.end() ){
4359 return (*it
).second
;
4365 Node
TheoryStrings::getMembership( Node n
, bool isPos
, unsigned i
) {
4366 return isPos
? d_pos_memberships_data
[n
][i
] : d_neg_memberships_data
[n
][i
];
4369 Node
TheoryStrings::mkRegExpAntec(Node atom
, Node ant
) {
4370 if(d_regexp_ant
.find(atom
) == d_regexp_ant
.end()) {
4371 return NodeManager::currentNM()->mkNode(kind::AND
, ant
, atom
);
4373 Node n
= d_regexp_ant
[atom
];
4374 return NodeManager::currentNM()->mkNode(kind::AND
, ant
, n
);
4378 void TheoryStrings::checkMemberships() {
4379 //add the memberships
4380 std::vector
<Node
> mems
= getExtTheory()->getActive(kind::STRING_IN_REGEXP
);
4381 for (unsigned i
= 0; i
< mems
.size(); i
++) {
4383 Assert( d_extf_info_tmp
.find( n
)!=d_extf_info_tmp
.end() );
4384 if( d_extf_info_tmp
[n
].d_pol
==1 || d_extf_info_tmp
[n
].d_pol
==-1 ){
4385 bool pol
= d_extf_info_tmp
[n
].d_pol
==1;
4386 Trace("strings-process-debug") << " add membership : " << n
<< ", pol = " << pol
<< std::endl
;
4387 addMembership( pol
? n
: n
.negate() );
4389 Trace("strings-process-debug") << " irrelevant (non-asserted) membership : " << n
<< std::endl
;
4393 bool addedLemma
= false;
4394 bool changed
= false;
4395 std::vector
< Node
> processed
;
4396 std::vector
< Node
> cprocessed
;
4398 Trace("regexp-debug") << "Checking Memberships ... " << std::endl
;
4399 //if(options::stringEIT()) {
4400 //TODO: Opt for normal forms
4401 for( NodeIntMap::const_iterator itr_xr
= d_pos_memberships
.begin(); itr_xr
!= d_pos_memberships
.end(); ++itr_xr
){
4402 bool spflag
= false;
4403 Node x
= (*itr_xr
).first
;
4404 Trace("regexp-debug") << "Checking Memberships for " << x
<< std::endl
;
4405 if(d_inter_index
.find(x
) == d_inter_index
.end()) {
4406 d_inter_index
[x
] = 0;
4408 int cur_inter_idx
= d_inter_index
[x
];
4409 unsigned n_pmem
= (*itr_xr
).second
;
4410 Assert( getNumMemberships( x
, true )==n_pmem
);
4411 if( cur_inter_idx
!= (int)n_pmem
) {
4413 d_inter_cache
[x
] = getMembership( x
, true, 0 );
4414 d_inter_index
[x
] = 1;
4415 Trace("regexp-debug") << "... only one choice " << std::endl
;
4416 } else if(n_pmem
> 1) {
4418 if(d_inter_cache
.find(x
) != d_inter_cache
.end()) {
4419 r
= d_inter_cache
[x
];
4422 r
= getMembership( x
, true, 0 );
4426 unsigned k_start
= cur_inter_idx
;
4427 Trace("regexp-debug") << "... staring from : " << cur_inter_idx
<< ", we have " << n_pmem
<< std::endl
;
4428 for(unsigned k
= k_start
; k
<n_pmem
; k
++) {
4429 Node r2
= getMembership( x
, true, k
);
4430 r
= d_regexp_opr
.intersect(r
, r2
, spflag
);
4433 } else if(r
== d_emptyRegexp
) {
4434 std::vector
< Node
> vec_nodes
;
4435 for( unsigned kk
=0; kk
<=k
; kk
++ ){
4436 Node rr
= getMembership( x
, true, kk
);
4437 Node n
= NodeManager::currentNM()->mkNode(kind::STRING_IN_REGEXP
, x
, rr
);
4438 vec_nodes
.push_back( n
);
4441 sendInference(vec_nodes
, conc
, "INTERSECT CONFLICT", true);
4450 if(!d_conflict
&& !spflag
) {
4451 d_inter_cache
[x
] = r
;
4452 d_inter_index
[x
] = (int)n_pmem
;
4459 Trace("regexp-debug") << "... No Intersect Conflict in Memberships, addedLemma: " << addedLemma
<< std::endl
;
4461 NodeManager
* nm
= NodeManager::currentNM();
4462 for( unsigned i
=0; i
<d_regexp_memberships
.size(); i
++ ) {
4463 //check regular expression membership
4464 Node assertion
= d_regexp_memberships
[i
];
4465 Trace("regexp-debug") << "Check : " << assertion
<< " " << (d_regexp_ucached
.find(assertion
) == d_regexp_ucached
.end()) << " " << (d_regexp_ccached
.find(assertion
) == d_regexp_ccached
.end()) << std::endl
;
4466 if( d_regexp_ucached
.find(assertion
) == d_regexp_ucached
.end()
4467 && d_regexp_ccached
.find(assertion
) == d_regexp_ccached
.end() ) {
4468 Trace("strings-regexp") << "We have regular expression assertion : " << assertion
<< std::endl
;
4469 Node atom
= assertion
.getKind()==kind::NOT
? assertion
[0] : assertion
;
4470 bool polarity
= assertion
.getKind()!=kind::NOT
;
4474 std::vector
< Node
> rnfexp
;
4478 x
= getNormalString(x
, rnfexp
);
4481 if (!d_regexp_opr
.checkConstRegExp(r
))
4483 r
= getNormalSymRegExp(r
, rnfexp
);
4486 Trace("strings-regexp-nf") << "Term " << atom
<< " is normalized to "
4487 << x
<< " IN " << r
<< std::endl
;
4491 Rewriter::rewrite(nm
->mkNode(kind::STRING_IN_REGEXP
, x
, r
));
4498 d_regexp_ccached
.insert(assertion
);
4501 else if (tmp
== d_false
)
4503 Node antec
= mkRegExpAntec(assertion
, mkExplain(rnfexp
));
4504 Node conc
= Node::null();
4505 sendLemma(antec
, conc
, "REGEXP NF Conflict");
4512 flag
= checkPDerivative(x
, r
, atom
, addedLemma
, rnfexp
);
4514 if(! options::stringExp()) {
4515 throw LogicException("Strings Incomplete (due to Negative Membership) by default, try --strings-exp option.");
4519 //check if the term is atomic
4520 Node xr
= getRepresentative( x
);
4521 //Trace("strings-regexp") << xr << " is rep of " << x << std::endl;
4522 //Assert( d_normal_forms.find( xr )!=d_normal_forms.end() );
4523 Trace("strings-regexp")
4524 << "Unroll/simplify membership of atomic term " << xr
4526 // if so, do simple unrolling
4527 std::vector
<Node
> nvec
;
4531 d_regexp_opr
.simplify(atom
, nvec
, polarity
);
4533 Node antec
= assertion
;
4534 if (d_regexp_ant
.find(assertion
) != d_regexp_ant
.end())
4536 antec
= d_regexp_ant
[assertion
];
4537 for (std::vector
<Node
>::const_iterator itr
= nvec
.begin();
4541 if (itr
->getKind() == kind::STRING_IN_REGEXP
)
4543 if (d_regexp_ant
.find(*itr
) == d_regexp_ant
.end())
4545 d_regexp_ant
[*itr
] = antec
;
4550 antec
= NodeManager::currentNM()->mkNode(
4551 kind::AND
, antec
, mkExplain(rnfexp
));
4552 Node conc
= nvec
.size() == 1
4554 : NodeManager::currentNM()->mkNode(kind::AND
, nvec
);
4555 conc
= Rewriter::rewrite(conc
);
4556 sendLemma(antec
, conc
, "REGEXP_Unfold");
4560 cprocessed
.push_back(assertion
);
4564 processed
.push_back(assertion
);
4566 // d_regexp_ucached[assertion] = true;
4576 for( unsigned i
=0; i
<processed
.size(); i
++ ) {
4577 Trace("strings-regexp") << "...add " << processed
[i
] << " to u-cache." << std::endl
;
4578 d_regexp_ucached
.insert(processed
[i
]);
4580 for( unsigned i
=0; i
<cprocessed
.size(); i
++ ) {
4581 Trace("strings-regexp") << "...add " << cprocessed
[i
] << " to c-cache." << std::endl
;
4582 d_regexp_ccached
.insert(cprocessed
[i
]);
4588 bool TheoryStrings::checkPDerivative( Node x
, Node r
, Node atom
, bool &addedLemma
, std::vector
< Node
> &nf_exp
) {
4590 Node antnf
= mkExplain(nf_exp
);
4592 if(areEqual(x
, d_emptyString
)) {
4594 switch(d_regexp_opr
.delta(r
, exp
)) {
4596 Node antec
= mkRegExpAntec(atom
, x
.eqNode(d_emptyString
));
4597 antec
= NodeManager::currentNM()->mkNode(kind::AND
, antec
, antnf
);
4598 sendLemma(antec
, exp
, "RegExp Delta");
4600 d_regexp_ccached
.insert(atom
);
4604 d_regexp_ccached
.insert(atom
);
4608 Node antec
= mkRegExpAntec(atom
, x
.eqNode(d_emptyString
));
4609 antec
= NodeManager::currentNM()->mkNode(kind::AND
, antec
, antnf
);
4610 Node conc
= Node::null();
4611 sendLemma(antec
, conc
, "RegExp Delta CONFLICT");
4613 d_regexp_ccached
.insert(atom
);
4621 /*Node xr = getRepresentative( x );
4623 Node n = NodeManager::currentNM()->mkNode(kind::STRING_IN_REGEXP, xr, r);
4624 Node nn = Rewriter::rewrite( n );
4626 d_regexp_ccached.insert(atom);
4628 } else if(nn == d_false) {
4629 Node antec = mkRegExpAntec(atom, x.eqNode(xr));
4630 Node conc = Node::null();
4631 sendLemma(antec, conc, "RegExp Delta CONFLICT");
4633 d_regexp_ccached.insert(atom);
4637 Node sREant
= mkRegExpAntec(atom
, d_true
);
4638 sREant
= NodeManager::currentNM()->mkNode(kind::AND
, sREant
, antnf
);
4639 if(deriveRegExp( x
, r
, sREant
)) {
4641 d_regexp_ccached
.insert(atom
);
4648 CVC4::String
TheoryStrings::getHeadConst( Node x
) {
4650 return x
.getConst
< String
>();
4651 } else if( x
.getKind() == kind::STRING_CONCAT
) {
4652 if( x
[0].isConst() ) {
4653 return x
[0].getConst
< String
>();
4655 return d_emptyString
.getConst
< String
>();
4658 return d_emptyString
.getConst
< String
>();
4662 bool TheoryStrings::deriveRegExp( Node x
, Node r
, Node ant
) {
4664 Assert(x
!= d_emptyString
);
4665 Trace("regexp-derive") << "TheoryStrings::deriveRegExp: x=" << x
<< ", r= " << r
<< std::endl
;
4667 // Node n = NodeManager::currentNM()->mkNode( kind::STRING_IN_REGEXP, x, r );
4668 // Node r = Rewriter::rewrite( n );
4670 // sendLemma(ant, r, "REGEXP REWRITE");
4674 CVC4::String s
= getHeadConst( x
);
4675 if( !s
.isEmptyString() && d_regexp_opr
.checkConstRegExp( r
) ) {
4676 Node conc
= Node::null();
4679 for(unsigned i
=0; i
<s
.size(); ++i
) {
4680 CVC4::String c
= s
.substr(i
, 1);
4682 int rt
= d_regexp_opr
.derivativeS(dc
, c
, dc2
);
4686 } else if(rt
== 2) {
4695 Assert(false, "Impossible: TheoryStrings::deriveRegExp: const string in const regular expression.");
4698 Assert( x
.getKind() == kind::STRING_CONCAT
);
4699 std::vector
< Node
> vec_nodes
;
4700 for(unsigned int i
=1; i
<x
.getNumChildren(); ++i
) {
4701 vec_nodes
.push_back( x
[i
] );
4703 Node left
= mkConcat( vec_nodes
);
4704 left
= Rewriter::rewrite( left
);
4705 conc
= NodeManager::currentNM()->mkNode( kind::STRING_IN_REGEXP
, left
, dc
);
4707 /*std::vector< Node > sdc;
4708 d_regexp_opr.simplify(conc, sdc, true);
4709 if(sdc.size() == 1) {
4712 conc = Rewriter::rewrite(NodeManager::currentNM()->mkNode(kind::AND, conc));
4716 sendLemma(ant
, conc
, "RegExp-Derive");
4723 void TheoryStrings::addMembership(Node assertion
) {
4724 bool polarity
= assertion
.getKind() != kind::NOT
;
4725 TNode atom
= polarity
? assertion
: assertion
[0];
4730 NodeIntMap::const_iterator it
= d_pos_memberships
.find( x
);
4731 if( it
!=d_nf_pairs
.end() ){
4732 index
= (*it
).second
;
4733 for( int k
=0; k
<index
; k
++ ){
4734 if( k
<(int)d_pos_memberships_data
[x
].size() ){
4735 if( d_pos_memberships_data
[x
][k
]==r
){
4743 d_pos_memberships
[x
] = index
+ 1;
4744 if( index
<(int)d_pos_memberships_data
[x
].size() ){
4745 d_pos_memberships_data
[x
][index
] = r
;
4747 d_pos_memberships_data
[x
].push_back( r
);
4749 } else if(!options::stringIgnNegMembership()) {
4750 /*if(options::stringEIT() && d_regexp_opr.checkConstRegExp(r)) {
4752 Node r2 = d_regexp_opr.complement(r, rt);
4753 Node a = NodeManager::currentNM()->mkNode(kind::STRING_IN_REGEXP, x, r2);
4756 NodeIntMap::const_iterator it
= d_neg_memberships
.find( x
);
4757 if( it
!=d_nf_pairs
.end() ){
4758 index
= (*it
).second
;
4759 for( int k
=0; k
<index
; k
++ ){
4760 if( k
<(int)d_neg_memberships_data
[x
].size() ){
4761 if( d_neg_memberships_data
[x
][k
]==r
){
4769 d_neg_memberships
[x
] = index
+ 1;
4770 if( index
<(int)d_neg_memberships_data
[x
].size() ){
4771 d_neg_memberships_data
[x
][index
] = r
;
4773 d_neg_memberships_data
[x
].push_back( r
);
4777 if(polarity
|| !options::stringIgnNegMembership()) {
4778 d_regexp_memberships
.push_back( assertion
);
4782 Node
TheoryStrings::getNormalString( Node x
, std::vector
< Node
>& nf_exp
){
4784 Node xr
= getRepresentative( x
);
4785 if( d_normal_forms
.find( xr
) != d_normal_forms
.end() ){
4786 Node ret
= mkConcat( d_normal_forms
[xr
] );
4787 nf_exp
.insert( nf_exp
.end(), d_normal_forms_exp
[xr
].begin(), d_normal_forms_exp
[xr
].end() );
4788 addToExplanation( x
, d_normal_forms_base
[xr
], nf_exp
);
4789 Trace("strings-debug") << "Term: " << x
<< " has a normal form " << ret
<< std::endl
;
4792 if(x
.getKind() == kind::STRING_CONCAT
) {
4793 std::vector
< Node
> vec_nodes
;
4794 for(unsigned i
=0; i
<x
.getNumChildren(); i
++) {
4795 Node nc
= getNormalString( x
[i
], nf_exp
);
4796 vec_nodes
.push_back( nc
);
4798 return mkConcat( vec_nodes
);
4805 Node
TheoryStrings::getNormalSymRegExp(Node r
, std::vector
<Node
> &nf_exp
) {
4807 switch( r
.getKind() ) {
4808 case kind::REGEXP_EMPTY
:
4809 case kind::REGEXP_SIGMA
:
4811 case kind::STRING_TO_REGEXP
: {
4812 if(!r
[0].isConst()) {
4813 Node tmp
= getNormalString( r
[0], nf_exp
);
4815 ret
= NodeManager::currentNM()->mkNode(kind::STRING_TO_REGEXP
, tmp
);
4820 case kind::REGEXP_CONCAT
:
4821 case kind::REGEXP_UNION
:
4822 case kind::REGEXP_INTER
:
4823 case kind::REGEXP_STAR
:
4825 std::vector
< Node
> vec_nodes
;
4826 for (const Node
& cr
: r
)
4828 vec_nodes
.push_back(getNormalSymRegExp(cr
, nf_exp
));
4830 ret
= Rewriter::rewrite(
4831 NodeManager::currentNM()->mkNode(r
.getKind(), vec_nodes
));
4834 //case kind::REGEXP_PLUS:
4835 //case kind::REGEXP_OPT:
4836 //case kind::REGEXP_RANGE:
4838 Trace("strings-error") << "Unsupported term: " << r
<< " in normalization SymRegExp." << std::endl
;
4840 //return Node::null();
4846 /** run the given inference step */
4847 void TheoryStrings::runInferStep(InferStep s
, int effort
)
4849 Trace("strings-process") << "Run " << s
;
4852 Trace("strings-process") << ", effort = " << effort
;
4854 Trace("strings-process") << "..." << std::endl
;
4857 case CHECK_INIT
: checkInit(); break;
4858 case CHECK_CONST_EQC
: checkConstantEquivalenceClasses(); break;
4859 case CHECK_EXTF_EVAL
: checkExtfEval(effort
); break;
4860 case CHECK_CYCLES
: checkCycles(); break;
4861 case CHECK_FLAT_FORMS
: checkFlatForms(); break;
4862 case CHECK_NORMAL_FORMS_EQ
: checkNormalFormsEq(); break;
4863 case CHECK_NORMAL_FORMS_DEQ
: checkNormalFormsDeq(); break;
4864 case CHECK_CODES
: checkCodes(); break;
4865 case CHECK_LENGTH_EQC
: checkLengthsEqc(); break;
4866 case CHECK_EXTF_REDUCTION
: checkExtfReductions(effort
); break;
4867 case CHECK_MEMBERSHIP
: checkMemberships(); break;
4868 case CHECK_CARDINALITY
: checkCardinality(); break;
4869 default: Unreachable(); break;
4871 Trace("strings-process") << "Done " << s
4872 << ", addedFact = " << !d_pending
.empty() << " "
4873 << !d_lemma_cache
.empty()
4874 << ", d_conflict = " << d_conflict
<< std::endl
;
4877 bool TheoryStrings::hasStrategyEffort(Effort e
) const
4879 return d_strat_steps
.find(e
) != d_strat_steps
.end();
4882 void TheoryStrings::addStrategyStep(InferStep s
, int effort
, bool addBreak
)
4884 // must run check init first
4885 Assert((s
== CHECK_INIT
)==d_infer_steps
.empty());
4886 // must use check cycles when using flat forms
4887 Assert(s
!= CHECK_FLAT_FORMS
4888 || std::find(d_infer_steps
.begin(), d_infer_steps
.end(), CHECK_CYCLES
)
4889 != d_infer_steps
.end());
4890 d_infer_steps
.push_back(s
);
4891 d_infer_step_effort
.push_back(effort
);
4894 d_infer_steps
.push_back(BREAK
);
4895 d_infer_step_effort
.push_back(0);
4899 void TheoryStrings::initializeStrategy()
4901 // initialize the strategy if not already done so
4902 if (!d_strategy_init
)
4904 std::map
<Effort
, unsigned> step_begin
;
4905 std::map
<Effort
, unsigned> step_end
;
4906 d_strategy_init
= true;
4907 // beginning indices
4908 step_begin
[EFFORT_FULL
] = 0;
4909 if (options::stringEager())
4911 step_begin
[EFFORT_STANDARD
] = 0;
4913 // add the inference steps
4914 addStrategyStep(CHECK_INIT
);
4915 addStrategyStep(CHECK_CONST_EQC
);
4916 addStrategyStep(CHECK_EXTF_EVAL
, 0);
4917 addStrategyStep(CHECK_CYCLES
);
4918 addStrategyStep(CHECK_FLAT_FORMS
);
4919 addStrategyStep(CHECK_EXTF_REDUCTION
, 1);
4920 if (options::stringEager())
4922 // do only the above inferences at standard effort, if applicable
4923 step_end
[EFFORT_STANDARD
] = d_infer_steps
.size() - 1;
4925 addStrategyStep(CHECK_NORMAL_FORMS_EQ
);
4926 addStrategyStep(CHECK_EXTF_EVAL
, 1);
4927 if (!options::stringEagerLen())
4929 addStrategyStep(CHECK_LENGTH_EQC
);
4931 addStrategyStep(CHECK_NORMAL_FORMS_DEQ
);
4932 addStrategyStep(CHECK_CODES
);
4933 if (options::stringEagerLen())
4935 addStrategyStep(CHECK_LENGTH_EQC
);
4937 if (options::stringExp() && !options::stringGuessModel())
4939 addStrategyStep(CHECK_EXTF_REDUCTION
, 2);
4941 addStrategyStep(CHECK_MEMBERSHIP
);
4942 addStrategyStep(CHECK_CARDINALITY
);
4943 step_end
[EFFORT_FULL
] = d_infer_steps
.size() - 1;
4944 if (options::stringExp() && options::stringGuessModel())
4946 step_begin
[EFFORT_LAST_CALL
] = d_infer_steps
.size();
4947 // these two steps are run in parallel
4948 addStrategyStep(CHECK_EXTF_REDUCTION
, 2, false);
4949 addStrategyStep(CHECK_EXTF_EVAL
, 3);
4950 step_end
[EFFORT_LAST_CALL
] = d_infer_steps
.size() - 1;
4952 // set the beginning/ending ranges
4953 for (const std::pair
<const Effort
, unsigned>& it_begin
: step_begin
)
4955 Effort e
= it_begin
.first
;
4956 std::map
<Effort
, unsigned>::iterator it_end
= step_end
.find(e
);
4957 Assert(it_end
!= step_end
.end());
4959 std::pair
<unsigned, unsigned>(it_begin
.second
, it_end
->second
);
4964 void TheoryStrings::runStrategy(unsigned sbegin
, unsigned send
)
4966 Trace("strings-process") << "----check, next round---" << std::endl
;
4967 for (unsigned i
= sbegin
; i
<= send
; i
++)
4969 InferStep curr
= d_infer_steps
[i
];
4979 runInferStep(curr
, d_infer_step_effort
[i
]);
4986 Trace("strings-process") << "----finished round---" << std::endl
;
4989 }/* CVC4::theory::strings namespace */
4990 }/* CVC4::theory namespace */
4991 }/* CVC4 namespace */