** Top contributors (to current version):
** Andrew Reynolds, Tianyi Liang, Morgan Deters
** This file is part of the CVC4 project.
- ** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS
+ ** Copyright (c) 2009-2019 by the authors listed in the file AUTHORS
** in the top-level source directory) and their institutional affiliations.
** All rights reserved. See the file COPYING in the top-level source
** directory for licensing information.\endverbatim
#include "smt/logic_exception.h"
#include "smt/smt_statistics_registry.h"
#include "theory/ext_theory.h"
-#include "theory/quantifiers/term_database.h"
#include "theory/rewriter.h"
#include "theory/strings/theory_strings_rewriter.h"
#include "theory/strings/type_enumerator.h"
d_pregistered_terms_cache(u),
d_registered_terms_cache(u),
d_length_lemma_terms_cache(u),
- d_skolem_ne_reg_cache(u),
- d_preproc(u),
- d_preproc_cache(u),
+ d_preproc(&d_sk_cache, u),
d_extf_infer_cache(c),
d_extf_infer_cache_u(u),
d_ee_disequalities(c),
d_functionsTerms(c),
d_has_extf(c, false),
d_has_str_code(false),
- d_regexp_memberships(c),
- d_regexp_ucached(u),
- d_regexp_ccached(c),
- d_pos_memberships(c),
- d_neg_memberships(c),
- d_inter_cache(c),
- d_inter_index(c),
- d_processed_memberships(c),
- d_regexp_ant(c),
+ d_regexp_solver(*this, c, u),
d_input_vars(u),
d_input_var_lsum(u),
d_cardinality_lits(u),
d_curr_cardinality(c, 0),
+ d_sslds(nullptr),
d_strategy_init(false)
{
setupExtTheory();
getExtTheory()->addFunctionKind(kind::STRING_ITOS);
getExtTheory()->addFunctionKind(kind::STRING_STOI);
getExtTheory()->addFunctionKind(kind::STRING_STRREPL);
+ getExtTheory()->addFunctionKind(kind::STRING_STRREPLALL);
getExtTheory()->addFunctionKind(kind::STRING_STRCTN);
getExtTheory()->addFunctionKind(kind::STRING_IN_REGEXP);
getExtTheory()->addFunctionKind(kind::STRING_LEQ);
d_equalityEngine.addFunctionKind(kind::STRING_CONCAT);
d_equalityEngine.addFunctionKind(kind::STRING_IN_REGEXP);
d_equalityEngine.addFunctionKind(kind::STRING_CODE);
- if( options::stringLazyPreproc() ){
- d_equalityEngine.addFunctionKind(kind::STRING_STRCTN);
- d_equalityEngine.addFunctionKind(kind::STRING_LEQ);
- d_equalityEngine.addFunctionKind(kind::STRING_SUBSTR);
- d_equalityEngine.addFunctionKind(kind::STRING_ITOS);
- d_equalityEngine.addFunctionKind(kind::STRING_STOI);
- d_equalityEngine.addFunctionKind(kind::STRING_STRIDOF);
- d_equalityEngine.addFunctionKind(kind::STRING_STRREPL);
- }
+
+ // extended functions
+ d_equalityEngine.addFunctionKind(kind::STRING_STRCTN);
+ d_equalityEngine.addFunctionKind(kind::STRING_LEQ);
+ d_equalityEngine.addFunctionKind(kind::STRING_SUBSTR);
+ d_equalityEngine.addFunctionKind(kind::STRING_ITOS);
+ d_equalityEngine.addFunctionKind(kind::STRING_STOI);
+ d_equalityEngine.addFunctionKind(kind::STRING_STRIDOF);
+ d_equalityEngine.addFunctionKind(kind::STRING_STRREPL);
+ d_equalityEngine.addFunctionKind(kind::STRING_STRREPLALL);
d_zero = NodeManager::currentNM()->mkConst( Rational( 0 ) );
d_one = NodeManager::currentNM()->mkConst( Rational( 1 ) );
d_neg_one = NodeManager::currentNM()->mkConst(Rational(-1));
d_emptyString = NodeManager::currentNM()->mkConst( ::CVC4::String("") );
- std::vector< Node > nvec;
- d_emptyRegexp = NodeManager::currentNM()->mkNode( kind::REGEXP_EMPTY, nvec );
d_true = NodeManager::currentNM()->mkConst( true );
d_false = NodeManager::currentNM()->mkConst( false );
return getLengthExp( t, exp, t );
}
+Node TheoryStrings::getNormalString(Node x, std::vector<Node>& nf_exp)
+{
+ if (!x.isConst())
+ {
+ Node xr = getRepresentative(x);
+ std::map<Node, NormalForm>::iterator it = d_normal_form.find(xr);
+ if (it != d_normal_form.end())
+ {
+ NormalForm& nf = it->second;
+ Node ret = mkConcat(nf.d_nf);
+ nf_exp.insert(nf_exp.end(), nf.d_exp.begin(), nf.d_exp.end());
+ addToExplanation(x, nf.d_base, nf_exp);
+ Trace("strings-debug")
+ << "Term: " << x << " has a normal form " << ret << std::endl;
+ return ret;
+ }
+ // if x does not have a normal form, then it should not occur in the
+ // equality engine and hence should be its own representative.
+ Assert(xr == x);
+ if (x.getKind() == kind::STRING_CONCAT)
+ {
+ std::vector<Node> vec_nodes;
+ for (unsigned i = 0; i < x.getNumChildren(); i++)
+ {
+ Node nc = getNormalString(x[i], nf_exp);
+ vec_nodes.push_back(nc);
+ }
+ return mkConcat(vec_nodes);
+ }
+ }
+ return x;
+}
+
void TheoryStrings::setMasterEqualityEngine(eq::EqualityEngine* eq) {
d_equalityEngine.setMasterEqualityEngine(eq);
}
Debug("strings") << "TheoryStrings::addSharedTerm(): "
<< t << " " << t.getType().isBoolean() << endl;
d_equalityEngine.addTriggerTerm(t, THEORY_STRINGS);
+ if (options::stringExp())
+ {
+ getExtTheory()->registerTermRec(t);
+ }
Debug("strings") << "TheoryStrings::addSharedTerm() finished" << std::endl;
}
}
}else if( effort>=1 && effort<3 && n.getType().isString() ){
//normal forms
- Node ns = getNormalString( d_normal_forms_base[nr], exp[n] );
+ NormalForm& nfnr = getNormalForm(nr);
+ Node ns = getNormalString(nfnr.d_base, exp[n]);
subs.push_back( ns );
- Trace("strings-subs") << " normal eqc : " << ns << " " << d_normal_forms_base[nr] << " " << nr << std::endl;
- if( !d_normal_forms_base[nr].isNull() ) {
- addToExplanation( n, d_normal_forms_base[nr], exp[n] );
+ Trace("strings-subs") << " normal eqc : " << ns << " " << nfnr.d_base
+ << " " << nr << std::endl;
+ if (!nfnr.d_base.isNull())
+ {
+ addToExplanation(n, nfnr.d_base, exp[n]);
}
}else{
//representative?
return true;
}
-int TheoryStrings::getReduction( int effort, Node n, Node& nr ) {
+bool TheoryStrings::doReduction(int effort, Node n, bool& isCd)
+{
+ Assert(d_extf_info_tmp.find(n) != d_extf_info_tmp.end());
+ if (!d_extf_info_tmp[n].d_model_active)
+ {
+ // n is not active in the model, no need to reduce
+ return false;
+ }
//determine the effort level to process the extf at
// 0 - at assertion time, 1+ - after no other reduction is applicable
- Assert( d_extf_info_tmp.find( n )!=d_extf_info_tmp.end() );
- if( d_extf_info_tmp[n].d_model_active ){
- int r_effort = -1;
- int pol = d_extf_info_tmp[n].d_pol;
- if( n.getKind()==kind::STRING_STRCTN ){
- if( pol==1 ){
- r_effort = 1;
- }else if( pol==-1 ){
- if( effort==2 ){
- Node x = n[0];
- Node s = n[1];
- std::vector< Node > lexp;
- Node lenx = getLength( x, lexp );
- Node lens = getLength( s, lexp );
- if( areEqual( lenx, lens ) ){
- Trace("strings-extf-debug") << " resolve extf : " << n << " based on equal lengths disequality." << std::endl;
- //we can reduce to disequality when lengths are equal
- if( !areDisequal( x, s ) ){
- lexp.push_back( lenx.eqNode(lens) );
- lexp.push_back( n.negate() );
- Node xneqs = x.eqNode(s).negate();
- sendInference( lexp, xneqs, "NEG-CTN-EQL", true );
- }
- return 1;
- }else{
- r_effort = 2;
- }
- }
- }
- }else{
- if( options::stringLazyPreproc() ){
- if( n.getKind()==kind::STRING_SUBSTR ){
- r_effort = 1;
- }else if( n.getKind()!=kind::STRING_IN_REGEXP ){
- r_effort = 2;
- }
- }
+ int r_effort = -1;
+ // polarity : 1 true, -1 false, 0 neither
+ int pol = 0;
+ Kind k = n.getKind();
+ if (n.getType().isBoolean() && !d_extf_info_tmp[n].d_const.isNull())
+ {
+ pol = d_extf_info_tmp[n].d_const.getConst<bool>() ? 1 : -1;
+ }
+ if (k == STRING_STRCTN)
+ {
+ if (pol == 1)
+ {
+ r_effort = 1;
}
- if( effort==r_effort ){
- Node c_n = pol==-1 ? n.negate() : n;
- if( d_preproc_cache.find( c_n )==d_preproc_cache.end() ){
- d_preproc_cache[ c_n ] = true;
- Trace("strings-process-debug") << "Process reduction for " << n << ", pol = " << pol << std::endl;
- Kind k = n.getKind();
- if (k == kind::STRING_STRCTN && pol == 1)
+ else if (pol == -1)
+ {
+ if (effort == 2)
+ {
+ Node x = n[0];
+ Node s = n[1];
+ std::vector<Node> lexp;
+ Node lenx = getLength(x, lexp);
+ Node lens = getLength(s, lexp);
+ if (areEqual(lenx, lens))
{
- Node x = n[0];
- Node s = n[1];
- //positive contains reduces to a equality
- Node sk1 = mkSkolemCached( x, s, sk_id_ctn_pre, "sc1" );
- Node sk2 = mkSkolemCached( x, s, sk_id_ctn_post, "sc2" );
- Node eq = Rewriter::rewrite( x.eqNode( mkConcat( sk1, s, sk2 ) ) );
- std::vector< Node > exp_vec;
- exp_vec.push_back( n );
- sendInference( d_empty_vec, exp_vec, eq, "POS-CTN", true );
- //we've reduced this n
- Trace("strings-extf-debug") << " resolve extf : " << n << " based on positive contain reduction." << std::endl;
- return 1;
+ Trace("strings-extf-debug")
+ << " resolve extf : " << n
+ << " based on equal lengths disequality." << std::endl;
+ // We can reduce negative contains to a disequality when lengths are
+ // equal. In other words, len( x ) = len( s ) implies
+ // ~contains( x, s ) reduces to x != s.
+ if (!areDisequal(x, s))
+ {
+ // len( x ) = len( s ) ^ ~contains( x, s ) => x != s
+ lexp.push_back(lenx.eqNode(lens));
+ lexp.push_back(n.negate());
+ Node xneqs = x.eqNode(s).negate();
+ sendInference(lexp, xneqs, "NEG-CTN-EQL", true);
+ }
+ // this depends on the current assertions, so we set that this
+ // inference is context-dependent.
+ isCd = true;
+ return true;
}
- else if (k != kind::STRING_CODE)
+ else
{
- Assert(k == STRING_SUBSTR || k == STRING_STRCTN || k == STRING_STRIDOF
- || k == STRING_ITOS
- || k == STRING_STOI
- || k == STRING_STRREPL
- || k == STRING_LEQ);
- std::vector< Node > new_nodes;
- Node res = d_preproc.simplify( n, new_nodes );
- Assert( res!=n );
- new_nodes.push_back( NodeManager::currentNM()->mkNode( kind::EQUAL, res, n ) );
- Node nnlem = new_nodes.size()==1 ? new_nodes[0] : NodeManager::currentNM()->mkNode( kind::AND, new_nodes );
- nnlem = Rewriter::rewrite( nnlem );
- Trace("strings-red-lemma") << "Reduction_" << effort << " lemma : " << nnlem << std::endl;
- Trace("strings-red-lemma") << "...from " << n << std::endl;
- sendInference( d_empty_vec, nnlem, "Reduction", true );
- //we've reduced this n
- Trace("strings-extf-debug") << " resolve extf : " << n << " based on reduction." << std::endl;
- return 1;
+ r_effort = 2;
}
- }else{
- return 1;
}
}
}
- return 0;
+ else
+ {
+ if (k == STRING_SUBSTR)
+ {
+ r_effort = 1;
+ }
+ else if (k != STRING_IN_REGEXP)
+ {
+ r_effort = 2;
+ }
+ }
+ if (effort != r_effort)
+ {
+ // not the right effort level to reduce
+ return false;
+ }
+ Node c_n = pol == -1 ? n.negate() : n;
+ Trace("strings-process-debug")
+ << "Process reduction for " << n << ", pol = " << pol << std::endl;
+ if (k == STRING_STRCTN && pol == 1)
+ {
+ Node x = n[0];
+ Node s = n[1];
+ // positive contains reduces to a equality
+ Node sk1 =
+ d_sk_cache.mkSkolemCached(x, s, SkolemCache::SK_FIRST_CTN_PRE, "sc1");
+ Node sk2 =
+ d_sk_cache.mkSkolemCached(x, s, SkolemCache::SK_FIRST_CTN_POST, "sc2");
+ Node eq = Rewriter::rewrite(x.eqNode(mkConcat(sk1, s, sk2)));
+ std::vector<Node> exp_vec;
+ exp_vec.push_back(n);
+ sendInference(d_empty_vec, exp_vec, eq, "POS-CTN", true);
+ Trace("strings-extf-debug")
+ << " resolve extf : " << n << " based on positive contain reduction."
+ << std::endl;
+ Trace("strings-red-lemma") << "Reduction (positive contains) lemma : " << n
+ << " => " << eq << std::endl;
+ // context-dependent because it depends on the polarity of n itself
+ isCd = true;
+ }
+ else if (k != kind::STRING_CODE)
+ {
+ NodeManager* nm = NodeManager::currentNM();
+ Assert(k == STRING_SUBSTR || k == STRING_STRCTN || k == STRING_STRIDOF
+ || k == STRING_ITOS || k == STRING_STOI || k == STRING_STRREPL
+ || k == STRING_STRREPLALL || k == STRING_LEQ);
+ std::vector<Node> new_nodes;
+ Node res = d_preproc.simplify(n, new_nodes);
+ Assert(res != n);
+ new_nodes.push_back(res.eqNode(n));
+ Node nnlem =
+ new_nodes.size() == 1 ? new_nodes[0] : nm->mkNode(AND, new_nodes);
+ nnlem = Rewriter::rewrite(nnlem);
+ Trace("strings-red-lemma")
+ << "Reduction_" << effort << " lemma : " << nnlem << std::endl;
+ Trace("strings-red-lemma") << "...from " << n << std::endl;
+ sendInference(d_empty_vec, nnlem, "Reduction", true);
+ Trace("strings-extf-debug")
+ << " resolve extf : " << n << " based on reduction." << std::endl;
+ isCd = false;
+ }
+ return true;
}
/////////////////////////////////////////////////////////////////////////////
void TheoryStrings::presolve() {
Debug("strings-presolve") << "TheoryStrings::Presolving : get fmf options " << (options::stringFMF() ? "true" : "false") << std::endl;
initializeStrategy();
+
+ // if strings fmf is enabled, register the strategy
+ if (options::stringFMF())
+ {
+ d_sslds.reset(new StringSumLengthDecisionStrategy(
+ getSatContext(), getUserContext(), d_valuation));
+ Trace("strings-dstrat-reg")
+ << "presolve: register decision strategy." << std::endl;
+ std::vector<Node> inputVars;
+ for (NodeSet::const_iterator itr = d_input_vars.begin();
+ itr != d_input_vars.end();
+ ++itr)
+ {
+ inputVars.push_back(*itr);
+ }
+ d_sslds->initialize(inputVars);
+ getDecisionManager()->registerStrategy(
+ DecisionManager::STRAT_STRINGS_SUM_LENGTHS, d_sslds.get());
+ }
}
{
Trace("strings-model") << "TheoryStrings : Collect model info" << std::endl;
Trace("strings-model") << "TheoryStrings : assertEqualityEngine." << std::endl;
-
- //AJR : no use doing this since we cannot preregister terms with finite types that don't belong to strings.
- // change this if we generalize to sequences.
- //set<Node> termSet;
- // Compute terms appearing in assertions and shared terms
- //computeRelevantTerms(termSet);
- //m->assertEqualityEngine( &d_equalityEngine, &termSet );
- if (!m->assertEqualityEngine(&d_equalityEngine))
+ std::set<Node> termSet;
+
+ // Compute terms appearing in assertions and shared terms
+ computeRelevantTerms(termSet);
+ // assert the (relevant) portion of the equality engine to the model
+ if (!m->assertEqualityEngine(&d_equalityEngine, &termSet))
{
return false;
}
+ std::unordered_set<Node, NodeHashFunction> repSet;
NodeManager* nm = NodeManager::currentNM();
// Generate model
- std::vector< Node > nodes;
- getEquivalenceClasses( nodes );
+ // get the relevant string equivalence classes
+ for (const Node& s : termSet)
+ {
+ if (s.getType().isString())
+ {
+ Node r = getRepresentative(s);
+ repSet.insert(r);
+ }
+ }
+ std::vector<Node> nodes(repSet.begin(), repSet.end());
std::map< Node, Node > processed;
std::vector< std::vector< Node > > col;
std::vector< Node > lts;
separateByLength( nodes, col, lts );
//step 1 : get all values for known lengths
std::vector< Node > lts_values;
- std::map< unsigned, bool > values_used;
+ std::map<unsigned, Node> values_used;
+ std::vector<Node> len_splits;
for( unsigned i=0; i<col.size(); i++ ) {
Trace("strings-model") << "Checking length for {";
for( unsigned j=0; j<col[i].size(); j++ ) {
Trace("strings-model") << col[i][j];
}
Trace("strings-model") << " } (length is " << lts[i] << ")" << std::endl;
+ Node len_value;
if( lts[i].isConst() ) {
- lts_values.push_back( lts[i] );
- Assert(lts[i].getConst<Rational>() <= Rational(String::maxSize()),
+ len_value = lts[i];
+ }
+ else if (!lts[i].isNull())
+ {
+ // get the model value for lts[i]
+ len_value = d_valuation.getModelValue(lts[i]);
+ }
+ if (len_value.isNull())
+ {
+ lts_values.push_back(Node::null());
+ }
+ else
+ {
+ Assert(len_value.getConst<Rational>() <= Rational(String::maxSize()),
"Exceeded UINT32_MAX in string model");
- unsigned lvalue = lts[i].getConst<Rational>().getNumerator().toUnsignedInt();
- values_used[ lvalue ] = true;
- }else{
- //get value for lts[i];
- if( !lts[i].isNull() ){
- Node v = d_valuation.getModelValue(lts[i]);
- Trace("strings-model") << "Model value for " << lts[i] << " is " << v << std::endl;
- lts_values.push_back( v );
- Assert(v.getConst<Rational>() <= Rational(String::maxSize()),
- "Exceeded UINT32_MAX in string model");
- unsigned lvalue = v.getConst<Rational>().getNumerator().toUnsignedInt();
- values_used[ lvalue ] = true;
- }else{
- //Trace("strings-model-warn") << "No length for eqc " << col[i][0] << std::endl;
- //Assert( false );
- lts_values.push_back( Node::null() );
+ unsigned lvalue =
+ len_value.getConst<Rational>().getNumerator().toUnsignedInt();
+ std::map<unsigned, Node>::iterator itvu = values_used.find(lvalue);
+ if (itvu == values_used.end())
+ {
+ values_used[lvalue] = lts[i];
+ }
+ else
+ {
+ len_splits.push_back(lts[i].eqNode(itvu->second));
}
+ lts_values.push_back(len_value);
}
}
////step 2 : assign arbitrary values for unknown lengths?
//step 3 : assign values to equivalence classes that are pure variables
for( unsigned i=0; i<col.size(); i++ ){
std::vector< Node > pure_eq;
- Trace("strings-model") << "The equivalence classes ";
+ Trace("strings-model") << "The (" << col[i].size()
+ << ") equivalence classes ";
for (const Node& eqc : col[i])
{
Trace("strings-model") << eqc << " ";
//check if col[i][j] has only variables
if (!eqc.isConst())
{
- Assert(d_normal_forms.find(eqc) != d_normal_forms.end());
- if (d_normal_forms[eqc].size() == 1)
+ NormalForm& nfe = getNormalForm(eqc);
+ if (nfe.d_nf.size() == 1)
{
// does it have a code and the length of these equivalence classes are
// one?
}
Trace("strings-model") << "*** Decide to make length of " << lvalue << std::endl;
lts_values[i] = nm->mkConst(Rational(lvalue));
- values_used[ lvalue ] = true;
+ values_used[lvalue] = Node::null();
}
Trace("strings-model") << "Need to assign values of length " << lts_values[i] << " to equivalence classes ";
for( unsigned j=0; j<pure_eq.size(); j++ ){
while (m->hasTerm(c))
{
++sel;
- Assert(!sel.isFinished());
+ if (sel.isFinished())
+ {
+ // We are in a case where model construction is impossible due to
+ // an insufficient number of constants of a given length.
+
+ // Consider an integer equivalence class E whose value is assigned
+ // n in the model. Let { S_1, ..., S_m } be the set of string
+ // equivalence classes such that len( x ) is a member of E for
+ // some member x of each class S1, ...,Sm. Since our calculus is
+ // saturated with respect to cardinality inference (see Liang
+ // et al, Figure 6, CAV 2014), we have that m <= A^n, where A is
+ // the cardinality of our alphabet.
+
+ // Now, consider the case where there exists two integer
+ // equivalence classes E1 and E2 that are assigned n, and moreover
+ // we did not received notification from arithmetic that E1 = E2.
+ // This typically should never happen, but assume in the following
+ // that it does.
+
+ // Now, it may be the case that there are string equivalence
+ // classes { S_1, ..., S_m1 } whose lengths are in E1,
+ // and classes { S'_1, ..., S'_m2 } whose lengths are in E2, where
+ // m1 + m2 > A^n. In this case, we have insufficient strings to
+ // assign to { S_1, ..., S_m1, S'_1, ..., S'_m2 }. If this
+ // happens, we add a split on len( u1 ) = len( u2 ) for some
+ // len( u1 ) in E1, len( u2 ) in E2. We do this for each pair of
+ // integer equivalence classes that are assigned to the same value
+ // in the model.
+ AlwaysAssert(!len_splits.empty());
+ for (const Node& sl : len_splits)
+ {
+ Node spl = nm->mkNode(OR, sl, sl.negate());
+ d_out->lemma(spl);
+ }
+ return false;
+ }
c = *sel;
}
++sel;
//step 4 : assign constants to all other equivalence classes
for( unsigned i=0; i<nodes.size(); i++ ){
if( processed.find( nodes[i] )==processed.end() ){
- Assert( d_normal_forms.find( nodes[i] )!=d_normal_forms.end() );
- Trace("strings-model") << "Construct model for " << nodes[i] << " based on normal form ";
- for( unsigned j=0; j<d_normal_forms[nodes[i]].size(); j++ ) {
- if( j>0 ) Trace("strings-model") << " ++ ";
- Trace("strings-model") << d_normal_forms[nodes[i]][j];
- Node r = getRepresentative( d_normal_forms[nodes[i]][j] );
- if( !r.isConst() && processed.find( r )==processed.end() ){
- Trace("strings-model") << "(UNPROCESSED)";
+ NormalForm& nf = getNormalForm(nodes[i]);
+ if (Trace.isOn("strings-model"))
+ {
+ Trace("strings-model")
+ << "Construct model for " << nodes[i] << " based on normal form ";
+ for (unsigned j = 0, size = nf.d_nf.size(); j < size; j++)
+ {
+ Node n = nf.d_nf[j];
+ if (j > 0)
+ {
+ Trace("strings-model") << " ++ ";
+ }
+ Trace("strings-model") << n;
+ Node r = getRepresentative(n);
+ if (!r.isConst() && processed.find(r) == processed.end())
+ {
+ Trace("strings-model") << "(UNPROCESSED)";
+ }
}
}
Trace("strings-model") << std::endl;
std::vector< Node > nc;
- for( unsigned j=0; j<d_normal_forms[nodes[i]].size(); j++ ) {
- Node r = getRepresentative( d_normal_forms[nodes[i]][j] );
+ for (const Node& n : nf.d_nf)
+ {
+ Node r = getRepresentative(n);
Assert( r.isConst() || processed.find( r )!=processed.end() );
nc.push_back(r.isConst() ? r : processed[r]);
}
Kind k = n.getKind();
if( !options::stringExp() ){
if (k == kind::STRING_STRIDOF || k == kind::STRING_ITOS
- || k == kind::STRING_STOI
- || k == kind::STRING_STRREPL
- || k == kind::STRING_STRCTN
+ || k == kind::STRING_STOI || k == kind::STRING_STRREPL
+ || k == kind::STRING_STRREPLALL || k == kind::STRING_STRCTN
|| k == STRING_LEQ)
{
std::stringstream ss;
// but not an internally generated Skolem, or a term that does
// not belong to this theory.
if (options::stringFMF()
- && (n.isVar() ? d_all_skolems.find(n) == d_all_skolems.end()
+ && (n.isVar() ? !d_sk_cache.isSkolem(n)
: kindToTheoryId(k) != THEORY_STRINGS))
{
d_input_vars.insert(n);
+ Trace("strings-dstrat-reg") << "input variable: " << n << std::endl;
}
d_equalityEngine.addTerm(n);
} else if (tn.isBoolean()) {
} else {
// Function applications/predicates
d_equalityEngine.addTerm(n);
- if( options::stringExp() ){
- //collect extended functions here: some may not be asserted to strings (such as those with return type Int),
- // but we need to record them so they are treated properly
- getExtTheory()->registerTermRec( n );
- }
}
- //concat terms do not contribute to theory combination? TODO: verify
- if (n.hasOperator() && kindToTheoryId(k) == THEORY_STRINGS
+ // Set d_functionsTerms stores all function applications that are
+ // relevant to theory combination. Notice that this is a subset of
+ // the applications whose kinds are function kinds in the equality
+ // engine. This means it does not include applications of operators
+ // like re.++, which is not a function kind in the equality engine.
+ // Concatenation terms do not need to be considered here because
+ // their arguments have string type and do not introduce any shared
+ // terms.
+ if (n.hasOperator() && d_equalityEngine.isFunctionKind(k)
&& k != kind::STRING_CONCAT)
{
d_functionsTerms.push_back( n );
bool TheoryStrings::needsCheckLastEffort() {
if( options::stringGuessModel() ){
- return d_has_extf.get();
+ return d_has_extf.get();
}else{
return false;
}
}
void TheoryStrings::checkExtfReductions( int effort ) {
- //standardize this?
- //std::vector< Node > nred;
- //getExtTheory()->doReductions( effort, nred, false );
-
+ // Notice we don't make a standard call to ExtTheory::doReductions here,
+ // since certain optimizations like context-dependent reductions and
+ // stratifying effort levels are done in doReduction below.
std::vector< Node > extf = getExtTheory()->getActive();
Trace("strings-process") << " checking " << extf.size() << " active extf"
<< std::endl;
for( unsigned i=0; i<extf.size(); i++ ){
+ Assert(!d_conflict);
Node n = extf[i];
Trace("strings-process") << " check " << n << ", active in model="
<< d_extf_info_tmp[n].d_model_active << std::endl;
- Node nr;
- int ret = getReduction( effort, n, nr );
- Assert( nr.isNull() );
- if( ret!=0 ){
- getExtTheory()->markReduced( extf[i] );
+ // whether the reduction was context-dependent
+ bool isCd = false;
+ bool ret = doReduction(effort, n, isCd);
+ if (ret)
+ {
+ getExtTheory()->markReduced(extf[i], isCd);
if (hasProcessed())
{
return;
}
}
+void TheoryStrings::checkMemberships()
+{
+ // add the memberships
+ std::vector<Node> mems = getExtTheory()->getActive(kind::STRING_IN_REGEXP);
+ for (unsigned i = 0; i < mems.size(); i++)
+ {
+ Node n = mems[i];
+ Assert(d_extf_info_tmp.find(n) != d_extf_info_tmp.end());
+ if (!d_extf_info_tmp[n].d_const.isNull())
+ {
+ bool pol = d_extf_info_tmp[n].d_const.getConst<bool>();
+ Trace("strings-process-debug")
+ << " add membership : " << n << ", pol = " << pol << std::endl;
+ d_regexp_solver.addMembership(pol ? n : n.negate());
+ }
+ else
+ {
+ Trace("strings-process-debug")
+ << " irrelevant (non-asserted) membership : " << n << std::endl;
+ }
+ }
+ d_regexp_solver.check();
+}
+
TheoryStrings::EqcInfo::EqcInfo(context::Context* c)
: d_length_term(c),
d_code_term(c),
}
}
-void TheoryStrings::addCarePairs( quantifiers::TermArgTrie * t1, quantifiers::TermArgTrie * t2, unsigned arity, unsigned depth ) {
+void TheoryStrings::addCarePairs(TNodeTrie* t1,
+ TNodeTrie* t2,
+ unsigned arity,
+ unsigned depth)
+{
if( depth==arity ){
if( t2!=NULL ){
- Node f1 = t1->getNodeData();
- Node f2 = t2->getNodeData();
+ Node f1 = t1->getData();
+ Node f2 = t2->getData();
if( !d_equalityEngine.areEqual( f1, f2 ) ){
Trace("strings-cg-debug") << "TheoryStrings::computeCareGraph(): checking function " << f1 << " and " << f2 << std::endl;
vector< pair<TNode, TNode> > currentPairs;
if( t2==NULL ){
if( depth<(arity-1) ){
//add care pairs internal to each child
- for( std::map< TNode, quantifiers::TermArgTrie >::iterator it = t1->d_data.begin(); it != t1->d_data.end(); ++it ){
- addCarePairs( &it->second, NULL, arity, depth+1 );
+ for (std::pair<const TNode, TNodeTrie>& tt : t1->d_data)
+ {
+ addCarePairs(&tt.second, nullptr, arity, depth + 1);
}
}
//add care pairs based on each pair of non-disequal arguments
- for( std::map< TNode, quantifiers::TermArgTrie >::iterator it = t1->d_data.begin(); it != t1->d_data.end(); ++it ){
- std::map< TNode, quantifiers::TermArgTrie >::iterator it2 = it;
+ for (std::map<TNode, TNodeTrie>::iterator it = t1->d_data.begin();
+ it != t1->d_data.end();
+ ++it)
+ {
+ std::map<TNode, TNodeTrie>::iterator it2 = it;
++it2;
for( ; it2 != t1->d_data.end(); ++it2 ){
if( !d_equalityEngine.areDisequal(it->first, it2->first, false) ){
}
}else{
//add care pairs based on product of indices, non-disequal arguments
- for( std::map< TNode, quantifiers::TermArgTrie >::iterator it = t1->d_data.begin(); it != t1->d_data.end(); ++it ){
- for( std::map< TNode, quantifiers::TermArgTrie >::iterator it2 = t2->d_data.begin(); it2 != t2->d_data.end(); ++it2 ){
- if( !d_equalityEngine.areDisequal(it->first, it2->first, false) ){
- if( !areCareDisequal(it->first, it2->first) ){
- addCarePairs( &it->second, &it2->second, arity, depth+1 );
+ for (std::pair<const TNode, TNodeTrie>& tt1 : t1->d_data)
+ {
+ for (std::pair<const TNode, TNodeTrie>& tt2 : t2->d_data)
+ {
+ if (!d_equalityEngine.areDisequal(tt1.first, tt2.first, false))
+ {
+ if (!areCareDisequal(tt1.first, tt2.first))
+ {
+ addCarePairs(&tt1.second, &tt2.second, arity, depth + 1);
}
}
}
void TheoryStrings::computeCareGraph(){
//computing the care graph here is probably still necessary, due to operators that take non-string arguments TODO: verify
Trace("strings-cg") << "TheoryStrings::computeCareGraph(): Build term indices..." << std::endl;
- std::map< Node, quantifiers::TermArgTrie > index;
+ std::map<Node, TNodeTrie> index;
std::map< Node, unsigned > arity;
unsigned functionTerms = d_functionsTerms.size();
for (unsigned i = 0; i < functionTerms; ++ i) {
}
}
//for each index
- for( std::map< Node, quantifiers::TermArgTrie >::iterator itii = index.begin(); itii != index.end(); ++itii ){
- Trace("strings-cg") << "TheoryStrings::computeCareGraph(): Process index " << itii->first << "..." << std::endl;
- addCarePairs( &itii->second, NULL, arity[ itii->first ], 0 );
+ for (std::pair<const Node, TNodeTrie>& tt : index)
+ {
+ Trace("strings-cg") << "TheoryStrings::computeCareGraph(): Process index "
+ << tt.first << "..." << std::endl;
+ addCarePairs(&tt.second, nullptr, arity[tt.first], 0);
}
}
//getExtTheory()->registerTerm( atom );
}
Trace("strings-pending-debug") << " Now collect terms" << std::endl;
- //collect extended function terms in the atom
+ // Collect extended function terms in the atom. Notice that we must register
+ // all extended functions occurring in assertions and shared terms. We
+ // make a similar call to registerTermRec in addSharedTerm.
getExtTheory()->registerTermRec( atom );
Trace("strings-pending-debug") << " Finished collect terms" << std::endl;
}
Trace("strings-process-debug") << " congruent term by singular : " << n << " " << c[0] << std::endl;
//singular case
if( !areEqual( c[0], n ) ){
+ Node ns;
std::vector< Node > exp;
//explain empty components
bool foundNEmpty = false;
}
}else{
Assert( !foundNEmpty );
- if( n[i]!=c[0] ){
- exp.push_back( n[i].eqNode( c[0] ) );
- }
+ ns = n[i];
foundNEmpty = true;
}
}
AlwaysAssert( foundNEmpty );
//infer the equality
- sendInference( exp, n.eqNode( c[0] ), "I_Norm_S" );
+ sendInference(exp, n.eqNode(ns), "I_Norm_S");
}
d_congruent.insert( n );
congruent[k]++;
Node n = terms[i];
Node sn = sterms[i];
//setup information about extf
- d_extf_info_tmp[n].init();
- std::map< Node, ExtfInfoTmp >::iterator itit = d_extf_info_tmp.find( n );
- if( n.getType().isBoolean() ){
- if( areEqual( n, d_true ) ){
- itit->second.d_pol = 1;
- }else if( areEqual( n, d_false ) ){
- itit->second.d_pol = -1;
- }
+ ExtfInfoTmp& einfo = d_extf_info_tmp[n];
+ Node r = getRepresentative(n);
+ std::map<Node, Node>::iterator itcit = d_eqc_to_const.find(r);
+ if (itcit != d_eqc_to_const.end())
+ {
+ einfo.d_const = itcit->second;
}
- Trace("strings-extf-debug") << "Check extf " << n << " == " << sn << ", pol = " << itit->second.d_pol << ", effort=" << effort << "..." << std::endl;
+ Trace("strings-extf-debug") << "Check extf " << n << " == " << sn
+ << ", constant = " << einfo.d_const
+ << ", effort=" << effort << "..." << std::endl;
//do the inference
Node to_reduce;
if( n!=sn ){
- itit->second.d_exp.insert( itit->second.d_exp.end(), exp[i].begin(), exp[i].end() );
+ einfo.d_exp.insert(einfo.d_exp.end(), exp[i].begin(), exp[i].end());
// inference is rewriting the substituted node
Node nrc = Rewriter::rewrite( sn );
//if rewrites to a constant, then do the inference and mark as reduced
}else{
conc = nrs.eqNode( nrc );
}
- itit->second.d_exp.clear();
+ einfo.d_exp.clear();
}
}else{
if( !areEqual( n, nrc ) ){
if( n.getType().isBoolean() ){
if( areEqual( n, nrc==d_true ? d_false : d_true ) ){
- itit->second.d_exp.push_back( nrc==d_true ? n.negate() : n );
+ einfo.d_exp.push_back(nrc == d_true ? n.negate() : n);
conc = d_false;
}else{
conc = nrc==d_true ? n : n.negate();
}
if( !conc.isNull() ){
Trace("strings-extf") << " resolve extf : " << sn << " -> " << nrc << std::endl;
- sendInference( itit->second.d_exp, conc, effort==0 ? "EXTF" : "EXTF-N", true );
+ sendInference(
+ einfo.d_exp, conc, effort == 0 ? "EXTF" : "EXTF-N", true);
if( d_conflict ){
Trace("strings-extf-debug") << " conflict, return." << std::endl;
return;
//check if it is already equal, if so, mark as reduced. Otherwise, do nothing.
if( areEqual( n, nrc ) ){
Trace("strings-extf") << " resolved extf, since satisfied by model: " << n << std::endl;
- itit->second.d_model_active = false;
+ einfo.d_model_active = false;
}
}
- //if it reduces to a conjunction, infer each and reduce
- }else if( ( nrc.getKind()==kind::OR && itit->second.d_pol==-1 ) || ( nrc.getKind()==kind::AND && itit->second.d_pol==1 ) ){
- Assert( effort<3 );
- getExtTheory()->markReduced( n );
- itit->second.d_exp.push_back( itit->second.d_pol==-1 ? n.negate() : n );
- Trace("strings-extf-debug") << " decomposable..." << std::endl;
- Trace("strings-extf") << " resolve extf : " << sn << " -> " << nrc << ", pol = " << itit->second.d_pol << std::endl;
- for( unsigned i=0; i<nrc.getNumChildren(); i++ ){
- sendInference( itit->second.d_exp, itit->second.d_pol==-1 ? nrc[i].negate() : nrc[i], effort==0 ? "EXTF_d" : "EXTF_d-N" );
+ }
+ else
+ {
+ // if this was a predicate which changed after substitution + rewriting
+ if (!einfo.d_const.isNull() && nrc.getType().isBoolean() && nrc != n)
+ {
+ bool pol = einfo.d_const == d_true;
+ Node nrcAssert = pol ? nrc : nrc.negate();
+ Node nAssert = pol ? n : n.negate();
+ Assert(effort < 3);
+ einfo.d_exp.push_back(nAssert);
+ Trace("strings-extf-debug") << " decomposable..." << std::endl;
+ Trace("strings-extf") << " resolve extf : " << sn << " -> " << nrc
+ << ", const = " << einfo.d_const << std::endl;
+ // We send inferences internal here, which may help show unsat.
+ // However, we do not make a determination whether n can be marked
+ // reduced since this argument may be circular: we may infer than n
+ // can be reduced to something else, but that thing may argue that it
+ // can be reduced to n, in theory.
+ sendInternalInference(
+ einfo.d_exp, nrcAssert, effort == 0 ? "EXTF_d" : "EXTF_d-N");
}
- }else{
to_reduce = nrc;
}
}else{
if( effort==1 ){
Trace("strings-extf") << " cannot rewrite extf : " << to_reduce << std::endl;
}
- checkExtfInference( n, to_reduce, itit->second, effort );
+ checkExtfInference(n, to_reduce, einfo, effort);
if( Trace.isOn("strings-extf-list") ){
Trace("strings-extf-list") << " * " << to_reduce;
- if( itit->second.d_pol!=0 ){
- Trace("strings-extf-list") << ", pol = " << itit->second.d_pol;
+ if (!einfo.d_const.isNull())
+ {
+ Trace("strings-extf-list") << ", const = " << einfo.d_const;
}
if( n!=to_reduce ){
Trace("strings-extf-list") << ", from " << n;
}
Trace("strings-extf-list") << std::endl;
- }
- if( getExtTheory()->isActive( n ) && itit->second.d_model_active ){
+ }
+ if (getExtTheory()->isActive(n) && einfo.d_model_active)
+ {
has_nreduce = true;
}
}
}
void TheoryStrings::checkExtfInference( Node n, Node nr, ExtfInfoTmp& in, int effort ){
- //make additional inferences that do not contribute to the reduction of n, but may help show a refutation
- if( in.d_pol!=0 ){
- //add original to explanation
- in.d_exp.push_back( in.d_pol==1 ? n : n.negate() );
-
- //d_extf_infer_cache stores whether we have made the inferences associated with a node n,
- // this may need to be generalized if multiple inferences apply
-
- if( nr.getKind()==kind::STRING_STRCTN ){
- if( ( in.d_pol==1 && nr[1].getKind()==kind::STRING_CONCAT ) || ( in.d_pol==-1 && nr[0].getKind()==kind::STRING_CONCAT ) ){
- if( d_extf_infer_cache.find( nr )==d_extf_infer_cache.end() ){
- d_extf_infer_cache.insert( nr );
-
- //one argument does (not) contain each of the components of the other argument
- int index = in.d_pol==1 ? 1 : 0;
- std::vector< Node > children;
- children.push_back( nr[0] );
- children.push_back( nr[1] );
- //Node exp_n = mkAnd( exp );
- for( unsigned i=0; i<nr[index].getNumChildren(); i++ ){
- children[index] = nr[index][i];
- Node conc = NodeManager::currentNM()->mkNode( kind::STRING_STRCTN, children );
- conc = Rewriter::rewrite(in.d_pol == 1 ? conc : conc.negate());
- // check if it already (does not) hold
- if (hasTerm(conc))
+ if (in.d_const.isNull())
+ {
+ return;
+ }
+ NodeManager* nm = NodeManager::currentNM();
+ Trace("strings-extf-infer") << "checkExtfInference: " << n << " : " << nr
+ << " == " << in.d_const << std::endl;
+
+ // add original to explanation
+ if (n.getType().isBoolean())
+ {
+ // if Boolean, it's easy
+ in.d_exp.push_back(in.d_const.getConst<bool>() ? n : n.negate());
+ }
+ else
+ {
+ // otherwise, must explain via base node
+ Node r = getRepresentative(n);
+ // we have that:
+ // d_eqc_to_const_exp[r] => d_eqc_to_const_base[r] = in.d_const
+ // thus:
+ // n = d_eqc_to_const_base[r] ^ d_eqc_to_const_exp[r] => n = in.d_const
+ Assert(d_eqc_to_const_base.find(r) != d_eqc_to_const_base.end());
+ addToExplanation(n, d_eqc_to_const_base[r], in.d_exp);
+ Assert(d_eqc_to_const_exp.find(r) != d_eqc_to_const_exp.end());
+ in.d_exp.insert(in.d_exp.end(),
+ d_eqc_to_const_exp[r].begin(),
+ d_eqc_to_const_exp[r].end());
+ }
+
+ // d_extf_infer_cache stores whether we have made the inferences associated
+ // with a node n,
+ // this may need to be generalized if multiple inferences apply
+
+ if (nr.getKind() == STRING_STRCTN)
+ {
+ Assert(in.d_const.isConst());
+ bool pol = in.d_const.getConst<bool>();
+ if ((pol && nr[1].getKind() == STRING_CONCAT)
+ || (!pol && nr[0].getKind() == STRING_CONCAT))
+ {
+ // If str.contains( x, str.++( y1, ..., yn ) ),
+ // we may infer str.contains( x, y1 ), ..., str.contains( x, yn )
+ // The following recognizes two situations related to the above reasoning:
+ // (1) If ~str.contains( x, yi ) holds for some i, we are in conflict,
+ // (2) If str.contains( x, yj ) already holds for some j, then the term
+ // str.contains( x, yj ) is irrelevant since it is satisfied by all models
+ // for str.contains( x, str.++( y1, ..., yn ) ).
+
+ // Notice that the dual of the above reasoning also holds, i.e.
+ // If ~str.contains( str.++( x1, ..., xn ), y ),
+ // we may infer ~str.contains( x1, y ), ..., ~str.contains( xn, y )
+ // This is also handled here.
+ if (d_extf_infer_cache.find(nr) == d_extf_infer_cache.end())
+ {
+ d_extf_infer_cache.insert(nr);
+
+ int index = pol ? 1 : 0;
+ std::vector<Node> children;
+ children.push_back(nr[0]);
+ children.push_back(nr[1]);
+ for (const Node& nrc : nr[index])
+ {
+ children[index] = nrc;
+ Node conc = nm->mkNode(STRING_STRCTN, children);
+ conc = Rewriter::rewrite(pol ? conc : conc.negate());
+ // check if it already (does not) hold
+ if (hasTerm(conc))
+ {
+ if (areEqual(conc, d_false))
{
- if (areEqual(conc, d_false))
- {
- // should be a conflict
- sendInference(in.d_exp, conc, "CTN_Decompose");
- }
- else if (getExtTheory()->hasFunctionKind(conc.getKind()))
- {
- // can mark as reduced, since model for n => model for conc
- getExtTheory()->markReduced(conc);
- }
+ // we are in conflict
+ sendInference(in.d_exp, conc, "CTN_Decompose");
+ }
+ else if (getExtTheory()->hasFunctionKind(conc.getKind()))
+ {
+ // can mark as reduced, since model for n implies model for conc
+ getExtTheory()->markReduced(conc);
}
}
-
}
- }else{
- //store this (reduced) assertion
- //Assert( effort==0 || nr[0]==getRepresentative( nr[0] ) );
- bool pol = in.d_pol==1;
- 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() ){
- Trace("strings-extf-debug") << " store contains info : " << nr[0] << " " << pol << " " << nr[1] << std::endl;
- d_extf_info_tmp[nr[0]].d_ctn[pol].push_back( nr[1] );
- d_extf_info_tmp[nr[0]].d_ctn_from[pol].push_back( n );
- //transitive closure for contains
- bool opol = !pol;
- for( unsigned i=0; i<d_extf_info_tmp[nr[0]].d_ctn[opol].size(); i++ ){
- Node onr = d_extf_info_tmp[nr[0]].d_ctn[opol][i];
- Node conc = NodeManager::currentNM()->mkNode( kind::STRING_STRCTN, pol ? nr[1] : onr, pol ? onr : nr[1] );
- conc = Rewriter::rewrite( conc );
- bool do_infer = false;
- if( conc.getKind()==kind::EQUAL ){
- do_infer = !areDisequal( conc[0], conc[1] );
- }else{
- do_infer = !areEqual( conc, d_false );
- }
- if( do_infer ){
- conc = conc.negate();
- std::vector< Node > exp_c;
- exp_c.insert( exp_c.end(), in.d_exp.begin(), in.d_exp.end() );
- Node ofrom = d_extf_info_tmp[nr[0]].d_ctn_from[opol][i];
- Assert( d_extf_info_tmp.find( ofrom )!=d_extf_info_tmp.end() );
- exp_c.insert( exp_c.end(), d_extf_info_tmp[ofrom].d_exp.begin(), d_extf_info_tmp[ofrom].d_exp.end() );
- sendInference( exp_c, conc, "CTN_Trans" );
- }
+ }
+ }
+ else
+ {
+ 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())
+ {
+ Trace("strings-extf-debug") << " store contains info : " << nr[0]
+ << " " << pol << " " << nr[1] << std::endl;
+ // Store s (does not) contains t, since nr = (~)contains( s, t ) holds.
+ d_extf_info_tmp[nr[0]].d_ctn[pol].push_back(nr[1]);
+ d_extf_info_tmp[nr[0]].d_ctn_from[pol].push_back(n);
+ // Do transistive closure on contains, e.g.
+ // if contains( s, t ) and ~contains( s, r ), then ~contains( t, r ).
+
+ // The following infers new (negative) contains based on the above
+ // reasoning, provided that ~contains( t, r ) does not
+ // already hold in the current context. We test this by checking that
+ // contains( t, r ) is not already asserted false in the current
+ // context. We also handle the case where contains( t, r ) is equivalent
+ // to t = r, in which case we check that t != r does not already hold
+ // in the current context.
+
+ // Notice that form of the above inference is enough to find
+ // conflicts purely due to contains predicates. For example, if we
+ // have only positive occurrences of contains, then no conflicts due to
+ // contains predicates are possible and this schema does nothing. For
+ // example, note that contains( s, t ) and contains( t, r ) implies
+ // contains( s, r ), which we could but choose not to infer. Instead,
+ // we prefer being lazy: only if ~contains( s, r ) appears later do we
+ // infer ~contains( t, r ), which suffices to show a conflict.
+ bool opol = !pol;
+ for (unsigned i = 0, size = d_extf_info_tmp[nr[0]].d_ctn[opol].size();
+ i < size;
+ i++)
+ {
+ Node onr = d_extf_info_tmp[nr[0]].d_ctn[opol][i];
+ Node conc =
+ nm->mkNode(STRING_STRCTN, pol ? nr[1] : onr, pol ? onr : nr[1]);
+ conc = Rewriter::rewrite(conc);
+ conc = conc.negate();
+ bool do_infer = false;
+ bool pol = conc.getKind() != NOT;
+ Node lit = pol ? conc : conc[0];
+ if (lit.getKind() == EQUAL)
+ {
+ do_infer = pol ? !areEqual(lit[0], lit[1])
+ : !areDisequal(lit[0], lit[1]);
+ }
+ else
+ {
+ do_infer = !areEqual(lit, pol ? d_true : d_false);
+ }
+ if (do_infer)
+ {
+ std::vector<Node> exp_c;
+ exp_c.insert(exp_c.end(), in.d_exp.begin(), in.d_exp.end());
+ Node ofrom = d_extf_info_tmp[nr[0]].d_ctn_from[opol][i];
+ Assert(d_extf_info_tmp.find(ofrom) != d_extf_info_tmp.end());
+ exp_c.insert(exp_c.end(),
+ d_extf_info_tmp[ofrom].d_exp.begin(),
+ d_extf_info_tmp[ofrom].d_exp.end());
+ sendInference(exp_c, conc, "CTN_Trans");
}
- }else{
- Trace("strings-extf-debug") << " redundant." << std::endl;
- getExtTheory()->markReduced( n );
}
}
+ else
+ {
+ // If we already know that s (does not) contain t, then n is redundant.
+ // For example, if str.contains( x, y ), str.contains( z, y ), and x=z
+ // are asserted in the current context, then str.contains( z, y ) is
+ // satisfied by all models of str.contains( x, y ) ^ x=z and thus can
+ // be ignored.
+ Trace("strings-extf-debug") << " redundant." << std::endl;
+ getExtTheory()->markReduced(n);
+ }
}
+ return;
+ }
+
+ // If it's not a predicate, see if we can solve the equality n = c, where c
+ // is the constant that extended term n is equal to.
+ Node inferEq = nr.eqNode(in.d_const);
+ Node inferEqr = Rewriter::rewrite(inferEq);
+ Node inferEqrr = inferEqr;
+ if (inferEqr.getKind() == EQUAL)
+ {
+ // try to use the extended rewriter for equalities
+ inferEqrr = TheoryStringsRewriter::rewriteEqualityExt(inferEqr);
+ }
+ if (inferEqrr != inferEqr)
+ {
+ inferEqrr = Rewriter::rewrite(inferEqrr);
+ Trace("strings-extf-infer") << "checkExtfInference: " << inferEq
+ << " ...reduces to " << inferEqrr << std::endl;
+ sendInternalInference(in.d_exp, inferEqrr, "EXTF_equality_rew");
}
}
}
// calculate normal forms for each equivalence class, possibly adding
// splitting lemmas
- d_normal_forms.clear();
- d_normal_forms_exp.clear();
+ d_normal_form.clear();
std::map<Node, Node> nf_to_eqc;
std::map<Node, Node> eqc_to_nf;
std::map<Node, Node> eqc_to_exp;
{
return;
}
- Node nf_term = mkConcat(d_normal_forms[eqc]);
+ NormalForm& nfe = getNormalForm(eqc);
+ Node nf_term = mkConcat(nfe.d_nf);
std::map<Node, Node>::iterator itn = nf_to_eqc.find(nf_term);
if (itn != nf_to_eqc.end())
{
+ NormalForm& nfe_eq = getNormalForm(itn->second);
// two equivalence classes have same normal form, merge
std::vector<Node> nf_exp;
- nf_exp.push_back(mkAnd(d_normal_forms_exp[eqc]));
+ nf_exp.push_back(mkAnd(nfe.d_exp));
nf_exp.push_back(eqc_to_exp[itn->second]);
- Node eq =
- d_normal_forms_base[eqc].eqNode(d_normal_forms_base[itn->second]);
+ Node eq = nfe.d_base.eqNode(nfe_eq.d_base);
sendInference(nf_exp, eq, "Normal_Form");
if( hasProcessed() ){
return;
{
nf_to_eqc[nf_term] = eqc;
eqc_to_nf[eqc] = nf_term;
- eqc_to_exp[eqc] = mkAnd(d_normal_forms_exp[eqc]);
+ eqc_to_exp[eqc] = mkAnd(nfe.d_exp);
}
Trace("strings-process-debug")
<< "Done verifying normal forms are the same for " << eqc << std::endl;
it != eqc_to_exp.end();
++it)
{
- Trace("strings-nf") << " N[" << it->first << "] (base "
- << d_normal_forms_base[it->first]
+ NormalForm& nf = getNormalForm(it->first);
+ Trace("strings-nf") << " N[" << it->first << "] (base " << nf.d_base
<< ") = " << eqc_to_nf[it->first] << std::endl;
Trace("strings-nf") << " exp: " << it->second << std::endl;
}
std::vector<Node> const_codes;
for (const Node& eqc : d_strings_eqc)
{
- if (d_normal_forms[eqc].size() == 1 && d_normal_forms[eqc][0].isConst())
+ NormalForm& nfe = getNormalForm(eqc);
+ if (nfe.d_nf.size() == 1 && nfe.d_nf[0].isConst())
{
- Node c = d_normal_forms[eqc][0];
+ Node c = nfe.d_nf[0];
Trace("strings-code-debug") << "Get proxy variable for " << c
<< std::endl;
Node cc = nm->mkNode(kind::STRING_CODE, c);
#endif
//do nothing
Trace("strings-process-debug") << "Return process equivalence class " << eqc << " : empty." << std::endl;
- d_normal_forms_base[eqc] = d_emptyString;
- d_normal_forms[eqc].clear();
- d_normal_forms_exp[eqc].clear();
+ d_normal_form[eqc].init(d_emptyString);
} else {
- Assert( d_normal_forms.find(eqc)==d_normal_forms.end() );
- //phi => t = s1 * ... * sn
- // normal form for each non-variable term in this eqc (s1...sn)
- std::vector< std::vector< Node > > normal_forms;
- // explanation for each normal form (phi)
- std::vector< std::vector< Node > > normal_forms_exp;
- // dependency information
- std::vector< std::map< Node, std::map< bool, int > > > normal_forms_exp_depend;
- // record terms for each normal form (t)
- std::vector< Node > normal_form_src;
- // get normal forms
- getNormalForms(eqc, normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend);
+ // should not have computed the normal form of this equivalence class yet
+ Assert(d_normal_form.find(eqc) == d_normal_form.end());
+ // Normal forms for the relevant terms in the equivalence class of eqc
+ std::vector<NormalForm> normal_forms;
+ // map each term to its index in the above vector
+ std::map<Node, unsigned> term_to_nf_index;
+ // get the normal forms
+ getNormalForms(eqc, normal_forms, term_to_nf_index);
if( hasProcessed() ){
return;
}
// process the normal forms
- processNEqc( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend );
+ processNEqc(normal_forms);
if( hasProcessed() ){
return;
}
- //debugPrintNormalForms( "strings-solve", eqc, normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend );
-
+ // debugPrintNormalForms( "strings-solve", eqc, normal_forms );
+
//construct the normal form
Assert( !normal_forms.empty() );
-
- int nf_index = 0;
- std::vector< Node >::iterator itn = std::find( normal_form_src.begin(), normal_form_src.end(), eqc );
- if( itn!=normal_form_src.end() ){
- nf_index = itn - normal_form_src.begin();
- Trace("strings-solve-debug2") << "take normal form " << nf_index << std::endl;
- Assert( normal_form_src[nf_index]==eqc );
- }else{
- //just take the first normal form
- Trace("strings-solve-debug2") << "take the first normal form" << std::endl;
- }
- d_normal_forms[eqc].insert( d_normal_forms[eqc].end(), normal_forms[nf_index].begin(), normal_forms[nf_index].end() );
- d_normal_forms_exp[eqc].insert( d_normal_forms_exp[eqc].end(), normal_forms_exp[nf_index].begin(), normal_forms_exp[nf_index].end() );
- Trace("strings-solve-debug2") << "take normal form ... done" << std::endl;
- d_normal_forms_base[eqc] = normal_form_src[nf_index];
- //track dependencies
- for( unsigned i=0; i<normal_forms_exp[nf_index].size(); i++ ){
- Node exp = normal_forms_exp[nf_index][i];
- for( unsigned r=0; r<2; r++ ){
- d_normal_forms_exp_depend[eqc][exp][r==0] = normal_forms_exp_depend[nf_index][exp][r==0];
- }
+ unsigned nf_index = 0;
+ std::map<Node, unsigned>::iterator it = term_to_nf_index.find(eqc);
+ // we prefer taking the normal form whose base is the equivalence
+ // class representative, since this leads to shorter explanations in
+ // some cases.
+ if (it != term_to_nf_index.end())
+ {
+ nf_index = it->second;
}
- Trace("strings-process-debug") << "Return process equivalence class " << eqc << " : returned, size = " << d_normal_forms[eqc].size() << std::endl;
+ d_normal_form[eqc] = normal_forms[nf_index];
+ Trace("strings-process-debug")
+ << "Return process equivalence class " << eqc
+ << " : returned, size = " << d_normal_form[eqc].d_nf.size()
+ << std::endl;
}
}
-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 ){
- if( std::find( nf_exp_n.begin(), nf_exp_n.end(), exp )==nf_exp_n.end() ){
- nf_exp_n.push_back( exp );
- }
- for( unsigned k=0; k<2; k++ ){
- int val = k==0 ? new_val : new_rev_val;
- std::map< bool, int >::iterator itned = nf_exp_depend_n[exp].find( k==1 );
- if( itned==nf_exp_depend_n[exp].end() ){
- Trace("strings-process-debug") << "Deps : set dependency on " << exp << " to " << val << " isRev=" << (k==0) << std::endl;
- nf_exp_depend_n[exp][k==1] = val;
- }else{
- Trace("strings-process-debug") << "Deps : Multiple dependencies on " << exp << " : " << itned->second << " " << val << " isRev=" << (k==0) << std::endl;
- //if we already have a dependency (in the case of non-linear string equalities), it is min/max
- bool cmp = val > itned->second;
- if( cmp==(k==1) ){
- nf_exp_depend_n[exp][k==1] = val;
- }
- }
+NormalForm& TheoryStrings::getNormalForm(Node n)
+{
+ std::map<Node, NormalForm>::iterator itn = d_normal_form.find(n);
+ if (itn == d_normal_form.end())
+ {
+ Trace("strings-warn") << "WARNING: returning empty normal form for " << n
+ << std::endl;
+ // Shouln't ask for normal forms of strings that weren't computed. This
+ // likely means that n is not a representative or not a term in the current
+ // context. We simply return a default normal form here in this case.
+ Assert(false);
+ return d_normal_form[n];
}
+ return itn->second;
}
-void TheoryStrings::getNormalForms( Node &eqc, std::vector< std::vector< Node > > &normal_forms, std::vector< Node > &normal_form_src,
- std::vector< std::vector< Node > > &normal_forms_exp, std::vector< std::map< Node, std::map< bool, int > > >& normal_forms_exp_depend ) {
+void TheoryStrings::getNormalForms(Node eqc,
+ std::vector<NormalForm>& normal_forms,
+ std::map<Node, unsigned>& term_to_nf_index)
+{
//constant for equivalence class
Node eqc_non_c = eqc;
Trace("strings-process-debug") << "Get normal forms " << eqc << std::endl;
while( !eqc_i.isFinished() ){
Node n = (*eqc_i);
if( d_congruent.find( n )==d_congruent.end() ){
- if( n.getKind() == kind::CONST_STRING || n.getKind() == kind::STRING_CONCAT ){
+ if (n.getKind() == CONST_STRING || n.getKind() == STRING_CONCAT)
+ {
Trace("strings-process-debug") << "Get Normal Form : Process term " << n << " in eqc " << eqc << std::endl;
- std::vector< Node > nf_n;
- std::vector< Node > nf_exp_n;
- std::map< Node, std::map< bool, int > > nf_exp_depend_n;
- if( n.getKind()==kind::CONST_STRING ){
- if( n!=d_emptyString ) {
- nf_n.push_back( n );
- }
- }else if( n.getKind()==kind::STRING_CONCAT ){
+ NormalForm nf_curr;
+ if (n.getKind() == CONST_STRING)
+ {
+ nf_curr.init(n);
+ }
+ else if (n.getKind() == STRING_CONCAT)
+ {
+ // set the base to n, we construct the other portions of nf_curr in
+ // the following.
+ nf_curr.d_base = n;
for( unsigned i=0; i<n.getNumChildren(); i++ ) {
Node nr = d_equalityEngine.getRepresentative( n[i] );
+ // get the normal form for the component
+ NormalForm& nfr = getNormalForm(nr);
+ std::vector<Node>& nfrv = nfr.d_nf;
Trace("strings-process-debug") << "Normalizing subterm " << n[i] << " = " << nr << std::endl;
- Assert( d_normal_forms.find( nr )!=d_normal_forms.end() );
- unsigned orig_size = nf_n.size();
- unsigned add_size = d_normal_forms[nr].size();
+ unsigned orig_size = nf_curr.d_nf.size();
+ unsigned add_size = nfrv.size();
//if not the empty string, add to current normal form
- if( !d_normal_forms[nr].empty() ){
- for( unsigned r=0; r<d_normal_forms[nr].size(); r++ ) {
- if( Trace.isOn("strings-error") ) {
- if( d_normal_forms[nr][r].getKind()==kind::STRING_CONCAT ){
- Trace("strings-error") << "Strings::Error: From eqc = " << eqc << ", " << n << " index " << i << ", bad normal form : ";
- for( unsigned rr=0; rr<d_normal_forms[nr].size(); rr++ ) {
- Trace("strings-error") << d_normal_forms[nr][rr] << " ";
+ if (!nfrv.empty())
+ {
+ // if in a build with assertions, we run the following block,
+ // which checks that normal forms do not have concat terms.
+ if (Configuration::isAssertionBuild())
+ {
+ for (const Node& nn : nfrv)
+ {
+ if (Trace.isOn("strings-error"))
+ {
+ if (nn.getKind() == STRING_CONCAT)
+ {
+ Trace("strings-error")
+ << "Strings::Error: From eqc = " << eqc << ", " << n
+ << " index " << i << ", bad normal form : ";
+ for (unsigned rr = 0; rr < nfrv.size(); rr++)
+ {
+ Trace("strings-error") << nfrv[rr] << " ";
+ }
+ Trace("strings-error") << std::endl;
}
- Trace("strings-error") << std::endl;
}
+ Assert(nn.getKind() != kind::STRING_CONCAT);
}
- Assert( d_normal_forms[nr][r].getKind()!=kind::STRING_CONCAT );
}
- nf_n.insert( nf_n.end(), d_normal_forms[nr].begin(), d_normal_forms[nr].end() );
+ nf_curr.d_nf.insert(nf_curr.d_nf.end(), nfrv.begin(), nfrv.end());
}
-
- for( unsigned j=0; j<d_normal_forms_exp[nr].size(); j++ ){
- Node exp = d_normal_forms_exp[nr][j];
- //track depends
- trackNfExpDependency( nf_exp_n, nf_exp_depend_n, exp,
- orig_size + d_normal_forms_exp_depend[nr][exp][false],
- orig_size + ( add_size - d_normal_forms_exp_depend[nr][exp][true] ) );
+ // Track explanation for the normal form. This is in two parts.
+ // First, we must carry the explanation of the normal form computed
+ // for the representative nr.
+ for (const Node& exp : nfr.d_exp)
+ {
+ // The explanation is only relevant for the subsegment it was
+ // previously relevant for, shifted now based on its relative
+ // placement in the normal form of n.
+ nf_curr.addToExplanation(
+ exp,
+ orig_size + nfr.d_expDep[exp][false],
+ orig_size + (add_size - nfr.d_expDep[exp][true]));
}
- if( d_normal_forms_base[nr]!=n[i] ){
- Assert( d_normal_forms_base.find( nr )!=d_normal_forms_base.end() );
- Node eq = n[i].eqNode( d_normal_forms_base[nr] );
- //track depends : entire current segment is dependent upon base equality
- trackNfExpDependency( nf_exp_n, nf_exp_depend_n, eq, orig_size, orig_size + add_size );
+ // Second, must explain that the component n[i] is equal to the
+ // base of the normal form for nr.
+ Node base = nfr.d_base;
+ if (base != n[i])
+ {
+ Node eq = n[i].eqNode(base);
+ // The equality is relevant for the entire current segment
+ nf_curr.addToExplanation(eq, orig_size, orig_size + add_size);
}
}
- //convert forward indices to reverse indices
- int total_size = nf_n.size();
- for( std::map< Node, std::map< bool, int > >::iterator it = nf_exp_depend_n.begin(); it != nf_exp_depend_n.end(); ++it ){
- it->second[true] = total_size - it->second[true];
- Assert( it->second[true]>=0 );
+ // Now that we are finished with the loop, we convert forward indices
+ // to reverse indices in the explanation dependency information
+ int total_size = nf_curr.d_nf.size();
+ for (std::pair<const Node, std::map<bool, unsigned> >& ed :
+ nf_curr.d_expDep)
+ {
+ ed.second[true] = total_size - ed.second[true];
+ Assert(ed.second[true] >= 0);
}
}
//if not equal to self
- if( nf_n.size()>1 || ( nf_n.size()==1 && nf_n[0].getKind()==kind::CONST_STRING ) ){
- if( nf_n.size()>1 ) {
- for( unsigned i=0; i<nf_n.size(); i++ ){
- if( Trace.isOn("strings-error") ){
- Trace("strings-error") << "Cycle for normal form ";
- printConcat(nf_n,"strings-error");
- Trace("strings-error") << "..." << nf_n[i] << std::endl;
+ std::vector<Node>& currv = nf_curr.d_nf;
+ if (currv.size() > 1
+ || (currv.size() == 1 && currv[0].getKind() == CONST_STRING))
+ {
+ // if in a build with assertions, check that normal form is acyclic
+ if (Configuration::isAssertionBuild())
+ {
+ if (currv.size() > 1)
+ {
+ for (unsigned i = 0; i < currv.size(); i++)
+ {
+ if (Trace.isOn("strings-error"))
+ {
+ Trace("strings-error") << "Cycle for normal form ";
+ printConcat(currv, "strings-error");
+ Trace("strings-error") << "..." << currv[i] << std::endl;
+ }
+ Assert(!areEqual(currv[i], n));
}
- Assert( !areEqual( nf_n[i], n ) );
}
}
- normal_forms.push_back(nf_n);
- normal_form_src.push_back(n);
- normal_forms_exp.push_back(nf_exp_n);
- normal_forms_exp_depend.push_back(nf_exp_depend_n);
+ term_to_nf_index[n] = normal_forms.size();
+ normal_forms.push_back(nf_curr);
}else{
//this was redundant: combination of self + empty string(s)
- Node nn = nf_n.size()==0 ? d_emptyString : nf_n[0];
+ Node nn = currv.size() == 0 ? d_emptyString : currv[0];
Assert( areEqual( nn, eqc ) );
}
}else{
if( normal_forms.empty() ) {
Trace("strings-solve-debug2") << "construct the normal form" << std::endl;
- //do not choose a concat here use "eqc_non_c" (in this case they have non-trivial explanation why they normalize to self)
- std::vector< Node > eqc_non_c_nf;
- getConcatVec( eqc_non_c, eqc_non_c_nf );
- normal_forms.push_back( eqc_non_c_nf );
- normal_form_src.push_back( eqc_non_c );
- normal_forms_exp.push_back( std::vector< Node >() );
- normal_forms_exp_depend.push_back( std::map< Node, std::map< bool, int > >() );
+ // This case happens when there are no non-trivial normal forms for this
+ // equivalence class. For example, given assertions:
+ // { x = y ++ z, x = y, z = "" }
+ // The equivalence class of { x, y, y ++ z } is such that the normal form
+ // of all terms is a variable (either x or y) in the equivalence class
+ // itself. Thus, the normal form of this equivalence class can be assigned
+ // to one of these variables.
+ // We use a non-concatenation term among the terms in this equivalence
+ // class, which is stored in eqc_non_c. The reason is this does not require
+ // an explanation, whereas e.g. y ++ z would require the explanation z = ""
+ // to justify its normal form is y.
+ Assert(eqc_non_c.getKind() != STRING_CONCAT);
+ NormalForm nf_triv;
+ nf_triv.init(eqc_non_c);
+ normal_forms.push_back(nf_triv);
}else{
if(Trace.isOn("strings-solve")) {
Trace("strings-solve") << "--- Normal forms for equivalance class " << eqc << " : " << std::endl;
- for( unsigned i=0; i<normal_forms.size(); i++ ) {
- Trace("strings-solve") << "#" << i << " (from " << normal_form_src[i] << ") : ";
- for( unsigned j=0; j<normal_forms[i].size(); j++ ) {
+ for (unsigned i = 0, size = normal_forms.size(); i < size; i++)
+ {
+ NormalForm& nf = normal_forms[i];
+ Trace("strings-solve") << "#" << i << " (from " << nf.d_base << ") : ";
+ for (unsigned j = 0, sizej = nf.d_nf.size(); j < sizej; j++)
+ {
if(j>0) {
Trace("strings-solve") << ", ";
}
- Trace("strings-solve") << normal_forms[i][j];
+ Trace("strings-solve") << nf.d_nf[j];
}
Trace("strings-solve") << std::endl;
Trace("strings-solve") << " Explanation is : ";
- if(normal_forms_exp[i].size() == 0) {
+ if (nf.d_exp.size() == 0)
+ {
Trace("strings-solve") << "NONE";
} else {
- for( unsigned j=0; j<normal_forms_exp[i].size(); j++ ) {
+ for (unsigned j = 0, sizej = nf.d_exp.size(); j < sizej; j++)
+ {
if(j>0) {
Trace("strings-solve") << " AND ";
}
- Trace("strings-solve") << normal_forms_exp[i][j];
+ Trace("strings-solve") << nf.d_exp[j];
}
Trace("strings-solve") << std::endl;
Trace("strings-solve") << "WITH DEPENDENCIES : " << std::endl;
- for( unsigned j=0; j<normal_forms_exp[i].size(); j++ ) {
- Trace("strings-solve") << " " << normal_forms_exp[i][j] << " -> ";
- Trace("strings-solve") << normal_forms_exp_depend[i][normal_forms_exp[i][j]][false] << ",";
- Trace("strings-solve") << normal_forms_exp_depend[i][normal_forms_exp[i][j]][true] << std::endl;
+ for (unsigned j = 0, sizej = nf.d_exp.size(); j < sizej; j++)
+ {
+ Node exp = nf.d_exp[j];
+ Trace("strings-solve") << " " << exp << " -> ";
+ Trace("strings-solve") << nf.d_expDep[exp][false] << ",";
+ Trace("strings-solve") << nf.d_expDep[exp][true] << std::endl;
}
}
Trace("strings-solve") << std::endl;
Node c = getConstantEqc( eqc );
if( !c.isNull() ){
Trace("strings-solve") << "Eqc is constant " << c << std::endl;
- for( unsigned i=0; i<normal_forms.size(); i++ ) {
+ for (unsigned i = 0, size = normal_forms.size(); i < size; i++)
+ {
+ NormalForm& nf = normal_forms[i];
int firstc, lastc;
- if( !TheoryStringsRewriter::canConstantContainList( c, normal_forms[i], firstc, lastc ) ){
- Node n = normal_form_src[i];
+ if (!TheoryStringsRewriter::canConstantContainList(
+ c, nf.d_nf, firstc, lastc))
+ {
+ Node n = nf.d_base;
//conflict
Trace("strings-solve") << "Normal form for " << n << " cannot be contained in constant " << c << std::endl;
//conflict, explanation is n = base ^ base = c ^ relevant porition of ( n = N[n] )
exp.push_back( d_eqc_to_const_exp[eqc] );
}
//TODO: this can be minimized based on firstc/lastc, normal_forms_exp_depend
- exp.insert( exp.end(), normal_forms_exp[i].begin(), normal_forms_exp[i].end() );
+ exp.insert(exp.end(), nf.d_exp.begin(), nf.d_exp.end());
Node conc = d_false;
sendInference( exp, conc, "N_NCTN" );
}
}
}
-void TheoryStrings::getExplanationVectorForPrefix( std::vector< std::vector< Node > > &normal_forms_exp, std::vector< std::map< Node, std::map< bool, int > > >& normal_forms_exp_depend,
- unsigned i, int index, bool isRev, std::vector< Node >& curr_exp ) {
- if( index==-1 || !options::stringMinPrefixExplain() ){
- curr_exp.insert(curr_exp.end(), normal_forms_exp[i].begin(), normal_forms_exp[i].end() );
- }else{
- for( unsigned k=0; k<normal_forms_exp[i].size(); k++ ){
- Node exp = normal_forms_exp[i][k];
- int dep = normal_forms_exp_depend[i][exp][isRev];
- if( dep<=index ){
- curr_exp.push_back( exp );
- Trace("strings-explain-prefix-debug") << " include : " << exp << std::endl;
- }else{
- Trace("strings-explain-prefix-debug") << " exclude : " << exp << std::endl;
- }
- }
- }
-}
-
-void TheoryStrings::getExplanationVectorForPrefixEq( std::vector< std::vector< Node > > &normal_forms, std::vector< Node > &normal_form_src,
- std::vector< std::vector< Node > > &normal_forms_exp, std::vector< std::map< Node, std::map< bool, int > > >& normal_forms_exp_depend,
- unsigned i, unsigned j, int index_i, int index_j, bool isRev, std::vector< Node >& curr_exp ) {
- Trace("strings-explain-prefix") << "Get explanation for prefix " << index_i << ", " << index_j << " of normal forms " << i << " and " << j << ", reverse = " << isRev << std::endl;
- for( unsigned r=0; r<2; r++ ){
- getExplanationVectorForPrefix( normal_forms_exp, normal_forms_exp_depend, r==0 ? i : j, r==0 ? index_i : index_j, isRev, curr_exp );
- }
- Trace("strings-explain-prefix") << "Included " << curr_exp.size() << " / " << ( normal_forms_exp[i].size() + normal_forms_exp[j].size() ) << std::endl;
- addToExplanation( normal_form_src[i], normal_form_src[j], curr_exp );
-}
-
-
-void TheoryStrings::processNEqc( std::vector< std::vector< Node > > &normal_forms, std::vector< Node > &normal_form_src,
- std::vector< std::vector< Node > > &normal_forms_exp, std::vector< std::map< Node, std::map< bool, int > > >& normal_forms_exp_depend ){
+void TheoryStrings::processNEqc(std::vector<NormalForm>& normal_forms)
+{
//the possible inferences
std::vector< InferInfo > pinfer;
// loop over all pairs
for(unsigned i=0; i<normal_forms.size()-1; i++) {
//unify each normalform[j] with normal_forms[i]
for(unsigned j=i+1; j<normal_forms.size(); j++ ) {
+ NormalForm& nfi = normal_forms[i];
+ NormalForm& nfj = normal_forms[j];
//ensure that normal_forms[i] and normal_forms[j] are the same modulo equality, add to pinfer if not
Trace("strings-solve") << "Strings: Process normal form #" << i << " against #" << j << "..." << std::endl;
- if( isNormalFormPair( normal_form_src[i], normal_form_src[j] ) ) {
+ if (isNormalFormPair(nfi.d_base, nfj.d_base))
+ {
Trace("strings-solve") << "Strings: Already cached." << std::endl;
}else{
//process the reverse direction first (check for easy conflicts and inferences)
unsigned rindex = 0;
- processReverseNEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, rindex, 0, pinfer );
+ nfi.reverse();
+ nfj.reverse();
+ processSimpleNEq(nfi, nfj, rindex, true, 0, pinfer);
+ nfi.reverse();
+ nfj.reverse();
if( hasProcessed() ){
return;
}else if( !pinfer.empty() && pinfer.back().d_id==1 ){
//rindex = 0;
unsigned index = 0;
- processSimpleNEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, index, false, rindex, pinfer );
+ processSimpleNEq(nfi, nfj, index, false, rindex, pinfer);
if( hasProcessed() ){
return;
}else if( !pinfer.empty() && pinfer.back().d_id==1 ){
}
}
}
- if( !pinfer.empty() ){
- //now, determine which of the possible inferences we want to add
- unsigned use_index = 0;
- bool set_use_index = false;
- Trace("strings-solve") << "Possible inferences (" << pinfer.size() << ") : " << std::endl;
- unsigned min_id = 9;
- unsigned max_index = 0;
- for (unsigned i = 0, size = pinfer.size(); i < size; i++)
+ if (pinfer.empty())
+ {
+ return;
+ }
+ // now, determine which of the possible inferences we want to add
+ unsigned use_index = 0;
+ bool set_use_index = false;
+ Trace("strings-solve") << "Possible inferences (" << pinfer.size()
+ << ") : " << std::endl;
+ unsigned min_id = 9;
+ unsigned max_index = 0;
+ for (unsigned i = 0, size = pinfer.size(); i < size; i++)
+ {
+ Trace("strings-solve") << "From " << pinfer[i].d_i << " / " << pinfer[i].d_j
+ << " (rev=" << pinfer[i].d_rev << ") : ";
+ Trace("strings-solve") << pinfer[i].d_conc << " by " << pinfer[i].d_id
+ << std::endl;
+ if (!set_use_index || pinfer[i].d_id < min_id
+ || (pinfer[i].d_id == min_id && pinfer[i].d_index > max_index))
{
- Trace("strings-solve") << "From " << pinfer[i].d_i << " / " << pinfer[i].d_j << " (rev=" << pinfer[i].d_rev << ") : ";
- Trace("strings-solve")
- << pinfer[i].d_conc << " by " << pinfer[i].d_id << std::endl;
- if (!set_use_index || pinfer[i].d_id < min_id
- || (pinfer[i].d_id == min_id && pinfer[i].d_index > max_index))
- {
- min_id = pinfer[i].d_id;
- max_index = pinfer[i].d_index;
- use_index = i;
- set_use_index = true;
- }
- }
- //send the inference
- if( !pinfer[use_index].d_nf_pair[0].isNull() ){
- Assert( !pinfer[use_index].d_nf_pair[1].isNull() );
- addNormalFormPair( pinfer[use_index].d_nf_pair[0], pinfer[use_index].d_nf_pair[1] );
- }
- std::stringstream ssi;
- ssi << pinfer[use_index].d_id;
- sendInference(pinfer[use_index].d_ant,
- pinfer[use_index].d_antn,
- pinfer[use_index].d_conc,
- ssi.str().c_str(),
- pinfer[use_index].sendAsLemma());
- 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 ){
- for( unsigned i=0; i<it->second.size(); i++ ){
- if( it->first==0 ){
- sendLengthLemma( it->second[i] );
- }else if( it->first==1 ){
- registerNonEmptySkolem( it->second[i] );
- }
- }
+ min_id = pinfer[i].d_id;
+ max_index = pinfer[i].d_index;
+ use_index = i;
+ set_use_index = true;
}
}
-}
+ // send the inference
+ if (!pinfer[use_index].d_nf_pair[0].isNull())
+ {
+ Assert(!pinfer[use_index].d_nf_pair[1].isNull());
+ addNormalFormPair(pinfer[use_index].d_nf_pair[0],
+ pinfer[use_index].d_nf_pair[1]);
+ }
+ std::stringstream ssi;
+ ssi << pinfer[use_index].d_id;
+ sendInference(pinfer[use_index].d_ant,
+ pinfer[use_index].d_antn,
+ pinfer[use_index].d_conc,
+ ssi.str().c_str(),
+ pinfer[use_index].sendAsLemma());
+ // Register the new skolems from this inference. We register them here
+ // (lazily), since the code above has now decided to use the inference
+ // at use_index that involves them.
+ for (const std::pair<const LengthStatus, std::vector<Node> >& sks :
+ pinfer[use_index].d_new_skolem)
+ {
+ for (const Node& n : sks.second)
+ {
+ registerLength(n, sks.first);
+ }
+ }
+}
bool TheoryStrings::InferInfo::sendAsLemma() {
return true;
}
-void TheoryStrings::processReverseNEq( std::vector< std::vector< Node > > &normal_forms, std::vector< Node > &normal_form_src,
- std::vector< std::vector< Node > > &normal_forms_exp, std::vector< std::map< Node, std::map< bool, int > > >& normal_forms_exp_depend,
- unsigned i, unsigned j, unsigned& index, unsigned rproc, std::vector< InferInfo >& pinfer ) {
- //reverse normal form of i, j
- std::reverse( normal_forms[i].begin(), normal_forms[i].end() );
- std::reverse( normal_forms[j].begin(), normal_forms[j].end() );
-
- processSimpleNEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, index, true, rproc, pinfer );
-
- //reverse normal form of i, j
- std::reverse( normal_forms[i].begin(), normal_forms[i].end() );
- std::reverse( normal_forms[j].begin(), normal_forms[j].end() );
-}
-
-//rproc is the # is the size of suffix that is identical
-void TheoryStrings::processSimpleNEq( std::vector< std::vector< Node > > &normal_forms, std::vector< Node > &normal_form_src,
- std::vector< std::vector< Node > > &normal_forms_exp, std::vector< std::map< Node, std::map< bool, int > > >& normal_forms_exp_depend,
- unsigned i, unsigned j, unsigned& index, bool isRev, unsigned rproc, std::vector< InferInfo >& pinfer ) {
- Assert( rproc<=normal_forms[i].size() && rproc<=normal_forms[j].size() );
+void TheoryStrings::processSimpleNEq(NormalForm& nfi,
+ NormalForm& nfj,
+ unsigned& index,
+ bool isRev,
+ unsigned rproc,
+ std::vector<InferInfo>& pinfer)
+{
+ std::vector<Node>& nfiv = nfi.d_nf;
+ std::vector<Node>& nfjv = nfj.d_nf;
+ NodeManager* nm = NodeManager::currentNM();
+ Assert(rproc <= nfiv.size() && rproc <= nfjv.size());
bool success;
do {
success = false;
//if we are at the end
- if( index==(normal_forms[i].size()-rproc) || index==(normal_forms[j].size()-rproc) ){
- if( index==(normal_forms[i].size()-rproc) && index==(normal_forms[j].size()-rproc) ){
+ if (index == (nfiv.size() - rproc) || index == (nfjv.size() - rproc))
+ {
+ if (index == (nfiv.size() - rproc) && index == (nfjv.size() - rproc))
+ {
//we're done
}else{
//the remainder must be empty
- unsigned k = index==(normal_forms[i].size()-rproc) ? j : i;
+ NormalForm& nfk = index == (nfiv.size() - rproc) ? nfj : nfi;
+ std::vector<Node>& nfkv = nfk.d_nf;
unsigned index_k = index;
//Node eq_exp = mkAnd( curr_exp );
std::vector< Node > curr_exp;
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, -1, -1, isRev, curr_exp );
- while( !d_conflict && index_k<(normal_forms[k].size()-rproc) ){
+ NormalForm::getExplanationForPrefixEq(nfi, nfj, -1, -1, curr_exp);
+ while (!d_conflict && index_k < (nfkv.size() - rproc))
+ {
//can infer that this string must be empty
- Node eq = normal_forms[k][index_k].eqNode( d_emptyString );
+ Node eq = nfkv[index_k].eqNode(d_emptyString);
//Trace("strings-lemma") << "Strings: Infer " << eq << " from " << eq_exp << std::endl;
- Assert( !areEqual( d_emptyString, normal_forms[k][index_k] ) );
+ Assert(!areEqual(d_emptyString, nfkv[index_k]));
sendInference( curr_exp, eq, "N_EndpointEmp" );
index_k++;
}
}
}else{
- Trace("strings-solve-debug") << "Process " << normal_forms[i][index] << " ... " << normal_forms[j][index] << std::endl;
- if( normal_forms[i][index]==normal_forms[j][index] ){
+ Trace("strings-solve-debug")
+ << "Process " << nfiv[index] << " ... " << nfjv[index] << std::endl;
+ if (nfiv[index] == nfjv[index])
+ {
Trace("strings-solve-debug") << "Simple Case 1 : strings are equal" << std::endl;
index++;
success = true;
}else{
- Assert( !areEqual(normal_forms[i][index], normal_forms[j][index]) );
+ Assert(!areEqual(nfiv[index], nfjv[index]));
std::vector< Node > temp_exp;
- Node length_term_i = getLength( normal_forms[i][index], temp_exp );
- Node length_term_j = getLength( normal_forms[j][index], temp_exp );
- //check length(normal_forms[i][index]) == length(normal_forms[j][index])
+ Node length_term_i = getLength(nfiv[index], temp_exp);
+ Node length_term_j = getLength(nfjv[index], temp_exp);
+ // check length(nfiv[index]) == length(nfjv[index])
if( areEqual( length_term_i, length_term_j ) ){
Trace("strings-solve-debug") << "Simple Case 2 : string lengths are equal" << std::endl;
- Node eq = normal_forms[i][index].eqNode( normal_forms[j][index] );
+ Node eq = nfiv[index].eqNode(nfjv[index]);
//eq = Rewriter::rewrite( eq );
Node length_eq = length_term_i.eqNode( length_term_j );
//temp_exp.insert(temp_exp.end(), curr_exp.begin(), curr_exp.end() );
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, index, index, isRev, temp_exp );
+ NormalForm::getExplanationForPrefixEq(
+ nfi, nfj, index, index, temp_exp);
temp_exp.push_back(length_eq);
sendInference( temp_exp, eq, "N_Unify" );
return;
- }else if( ( normal_forms[i][index].getKind()!=kind::CONST_STRING && index==normal_forms[i].size()-rproc-1 ) ||
- ( normal_forms[j][index].getKind()!=kind::CONST_STRING && index==normal_forms[j].size()-rproc-1 ) ){
+ }
+ else if ((nfiv[index].getKind() != CONST_STRING
+ && index == nfiv.size() - rproc - 1)
+ || (nfjv[index].getKind() != CONST_STRING
+ && index == nfjv.size() - rproc - 1))
+ {
Trace("strings-solve-debug") << "Simple Case 3 : at endpoint" << std::endl;
std::vector< Node > antec;
//antec.insert(antec.end(), curr_exp.begin(), curr_exp.end() );
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, -1, -1, isRev, antec );
+ NormalForm::getExplanationForPrefixEq(nfi, nfj, -1, -1, antec);
std::vector< Node > eqn;
for( unsigned r=0; r<2; r++ ) {
- int index_k = index;
- int k = r==0 ? i : j;
+ NormalForm& nfk = r == 0 ? nfi : nfj;
+ std::vector<Node>& nfkv = nfk.d_nf;
std::vector< Node > eqnc;
- for( unsigned index_l=index_k; index_l<(normal_forms[k].size()-rproc); index_l++ ) {
+ for (unsigned index_l = index, size = (nfkv.size() - rproc);
+ index_l < size;
+ index_l++)
+ {
if(isRev) {
- eqnc.insert(eqnc.begin(), normal_forms[k][index_l] );
+ eqnc.insert(eqnc.begin(), nfkv[index_l]);
} else {
- eqnc.push_back( normal_forms[k][index_l] );
+ eqnc.push_back(nfkv[index_l]);
}
}
eqn.push_back( mkConcat( eqnc ) );
sendInference( antec, eqn[0].eqNode( eqn[1] ), "N_EndpointEq", true );
return;
}else{
- Assert( normal_forms[i].size()==normal_forms[j].size() );
- index = normal_forms[i].size()-rproc;
+ Assert(nfiv.size() == nfjv.size());
+ index = nfiv.size() - rproc;
}
- }else if( normal_forms[i][index].isConst() && normal_forms[j][index].isConst() ){
- Node const_str = normal_forms[i][index];
- Node other_str = normal_forms[j][index];
+ }
+ else if (nfiv[index].isConst() && nfjv[index].isConst())
+ {
+ Node const_str = nfiv[index];
+ Node other_str = nfjv[index];
Trace("strings-solve-debug") << "Simple Case 3 : Const Split : " << const_str << " vs " << other_str << " at index " << index << ", isRev = " << isRev << std::endl;
unsigned len_short = const_str.getConst<String>().size() <= other_str.getConst<String>().size() ? const_str.getConst<String>().size() : other_str.getConst<String>().size();
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);
if( isSameFix ) {
//same prefix/suffix
+ bool constCmp = const_str.getConst<String>().size()
+ < other_str.getConst<String>().size();
//k is the index of the string that is shorter
- int k = const_str.getConst<String>().size()<other_str.getConst<String>().size() ? i : j;
- int l = const_str.getConst<String>().size()<other_str.getConst<String>().size() ? j : i;
- //update the nf exp dependencies
- //notice this is not critical for soundness: not doing the below incrementing will only lead to overapproximating when antecedants are required in explanations
- for( std::map< Node, std::map< bool, int > >::iterator itnd = normal_forms_exp_depend[l].begin(); itnd != normal_forms_exp_depend[l].end(); ++itnd ){
- for( std::map< bool, int >::iterator itnd2 = itnd->second.begin(); itnd2 != itnd->second.end(); ++itnd2 ){
- //see if this can be incremented: it can if it is not relevant to the current index
- Assert( itnd2->second>=0 && itnd2->second<=(int)normal_forms[l].size() );
- bool increment = (itnd2->first==isRev) ? itnd2->second>(int)index : ( (int)normal_forms[l].size()-1-itnd2->second )<(int)index;
- if( increment ){
- normal_forms_exp_depend[l][itnd->first][itnd2->first] = itnd2->second + 1;
- }
- }
- }
+ NormalForm& nfk = constCmp ? nfi : nfj;
+ std::vector<Node>& nfkv = nfk.d_nf;
+ NormalForm& nfl = constCmp ? nfj : nfi;
+ std::vector<Node>& nflv = nfl.d_nf;
+ Node remainderStr;
if( isRev ){
- int new_len = normal_forms[l][index].getConst<String>().size() - len_short;
- Node remainderStr = NodeManager::currentNM()->mkConst( normal_forms[l][index].getConst<String>().substr(0, new_len) );
- Trace("strings-solve-debug-test") << "Break normal form of " << normal_forms[l][index] << " into " << normal_forms[k][index] << ", " << remainderStr << std::endl;
- normal_forms[l].insert( normal_forms[l].begin()+index + 1, remainderStr );
+ int new_len = nflv[index].getConst<String>().size() - len_short;
+ remainderStr = nm->mkConst(
+ nflv[index].getConst<String>().substr(0, new_len));
}else{
- Node remainderStr = NodeManager::currentNM()->mkConst(normal_forms[l][index].getConst<String>().substr(len_short));
- Trace("strings-solve-debug-test") << "Break normal form of " << normal_forms[l][index] << " into " << normal_forms[k][index] << ", " << remainderStr << std::endl;
- normal_forms[l].insert( normal_forms[l].begin()+index + 1, remainderStr );
+ remainderStr =
+ nm->mkConst(nflv[index].getConst<String>().substr(len_short));
}
- normal_forms[l][index] = normal_forms[k][index];
+ Trace("strings-solve-debug-test")
+ << "Break normal form of " << nflv[index] << " into "
+ << nfkv[index] << ", " << remainderStr << std::endl;
+ nfl.splitConstant(index, nfkv[index], remainderStr);
index++;
success = true;
}else{
//conflict
std::vector< Node > antec;
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, index, index, isRev, antec );
+ NormalForm::getExplanationForPrefixEq(
+ nfi, nfj, index, index, antec);
sendInference( antec, d_false, "N_Const", true );
return;
}
InferInfo info;
info.d_index = index;
//for debugging
- info.d_i = i;
- info.d_j = j;
+ info.d_i = nfi.d_base;
+ info.d_j = nfj.d_base;
info.d_rev = isRev;
bool info_valid = false;
- Assert( index<normal_forms[i].size()-rproc && index<normal_forms[j].size()-rproc );
+ Assert(index < nfiv.size() - rproc && index < nfjv.size() - rproc);
std::vector< Node > lexp;
- Node length_term_i = getLength( normal_forms[i][index], lexp );
- Node length_term_j = getLength( normal_forms[j][index], lexp );
+ Node length_term_i = getLength(nfiv[index], lexp);
+ Node length_term_j = getLength(nfjv[index], lexp);
//split on equality between string lengths (note that splitting on equality between strings is worse since it is harder to process)
- if( !areDisequal( length_term_i, length_term_j ) && !areEqual( length_term_i, length_term_j ) &&
- normal_forms[i][index].getKind()!=kind::CONST_STRING && normal_forms[j][index].getKind()!=kind::CONST_STRING ){ //AJR: remove the latter 2 conditions?
+ if (!areDisequal(length_term_i, length_term_j)
+ && !areEqual(length_term_i, length_term_j)
+ && !nfiv[index].isConst() && !nfjv[index].isConst())
+ { // AJR: remove the latter 2 conditions?
Trace("strings-solve-debug") << "Non-simple Case 1 : string lengths neither equal nor disequal" << std::endl;
//try to make the lengths equal via splitting on demand
Node length_eq = NodeManager::currentNM()->mkNode( kind::EQUAL, length_term_i, length_term_j );
Trace("strings-solve-debug") << "Non-simple Case 2 : must compare strings" << std::endl;
int loop_in_i = -1;
int loop_in_j = -1;
- if( detectLoop( normal_forms, i, j, index, loop_in_i, loop_in_j, rproc ) ){
+ ProcessLoopResult plr = ProcessLoopResult::SKIPPED;
+ if (detectLoop(nfi, nfj, index, loop_in_i, loop_in_j, rproc))
+ {
if( !isRev ){ //FIXME
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, -1, -1, isRev, info.d_ant );
- //set info
- 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 ) ){
- info_valid = true;
- }
+ NormalForm::getExplanationForPrefixEq(
+ nfi, nfj, -1, -1, info.d_ant);
+ // set info
+ plr = processLoop(loop_in_i != -1 ? nfi : nfj,
+ loop_in_i != -1 ? nfj : nfi,
+ loop_in_i != -1 ? loop_in_i : loop_in_j,
+ index,
+ info);
+ if (plr == ProcessLoopResult::INFERENCE)
+ {
+ info_valid = true;
+ }
}
- }else{
+ }
+
+ if (plr == ProcessLoopResult::SKIPPED)
+ {
//AJR: length entailment here?
- if( normal_forms[i][index].getKind() == kind::CONST_STRING || normal_forms[j][index].getKind() == kind::CONST_STRING ){
- unsigned const_k = normal_forms[i][index].getKind() == kind::CONST_STRING ? i : j;
- unsigned nconst_k = normal_forms[i][index].getKind() == kind::CONST_STRING ? j : i;
- Node other_str = normal_forms[nconst_k][index];
+ if (nfiv[index].isConst() || nfjv[index].isConst())
+ {
+ NormalForm& nfc = nfiv[index].isConst() ? nfi : nfj;
+ std::vector<Node>& nfcv = nfc.d_nf;
+ NormalForm& nfnc = nfiv[index].isConst() ? nfj : nfi;
+ std::vector<Node>& nfncv = nfnc.d_nf;
+ Node other_str = nfncv[index];
Assert( other_str.getKind()!=kind::CONST_STRING, "Other string is not constant." );
Assert( other_str.getKind()!=kind::STRING_CONCAT, "Other string is not CONCAT." );
if( !d_equalityEngine.areDisequal( other_str, d_emptyString, true ) ){
if( !isRev ){ //FIXME
Node xnz = other_str.eqNode( d_emptyString ).negate();
unsigned index_nc_k = index+1;
- //Node next_const_str = TheoryStringsRewriter::collectConstantStringAt( normal_forms[nconst_k], index_nc_k, false );
unsigned start_index_nc_k = index+1;
- Node next_const_str = TheoryStringsRewriter::getNextConstantAt( normal_forms[nconst_k], start_index_nc_k, index_nc_k, false );
+ Node next_const_str =
+ TheoryStringsRewriter::getNextConstantAt(
+ nfncv, start_index_nc_k, index_nc_k, false);
if( !next_const_str.isNull() ) {
unsigned index_c_k = index;
- Node const_str = TheoryStringsRewriter::collectConstantStringAt( normal_forms[const_k], index_c_k, false );
+ Node const_str =
+ TheoryStringsRewriter::collectConstantStringAt(
+ nfcv, index_c_k, false);
Assert( !const_str.isNull() );
CVC4::String stra = const_str.getConst<String>();
CVC4::String strb = next_const_str.getConst<String>();
}
if( p>1 ){
if( start_index_nc_k==index+1 ){
- info.d_ant.push_back( xnz );
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend,
- const_k, nconst_k, index_c_k, index_nc_k, isRev, info.d_ant );
+ info.d_ant.push_back(xnz);
+ NormalForm::getExplanationForPrefixEq(
+ nfc, nfnc, index_c_k, index_nc_k, info.d_ant);
Node prea = p==stra.size() ? const_str : NodeManager::currentNM()->mkConst( isRev ? stra.suffix( p ) : stra.prefix( p ) );
- Node sk = mkSkolemCached( other_str, prea, isRev ? sk_id_c_spt_rev : sk_id_c_spt, "c_spt", -1 );
+ Node sk = d_sk_cache.mkSkolemCached(
+ other_str,
+ prea,
+ isRev ? SkolemCache::SK_ID_C_SPT_REV
+ : SkolemCache::SK_ID_C_SPT,
+ "c_spt");
Trace("strings-csp") << "Const Split: " << prea << " is removed from " << stra << " due to " << strb << ", p=" << p << std::endl;
//set info
info.d_conc = other_str.eqNode( isRev ? mkConcat( sk, prea ) : mkConcat(prea, sk) );
- info.d_new_skolem[0].push_back( sk );
+ info.d_new_skolem[LENGTH_SPLIT].push_back(sk);
info.d_id = INFER_SSPLIT_CST_PROP;
info_valid = true;
}
- /* FIXME for isRev, speculative
- else if( options::stringLenPropCsp() ){
- //propagate length constraint
- std::vector< Node > cc;
- for( unsigned i=index; i<start_index_nc_k; i++ ){
- cc.push_back( normal_forms[nconst_k][i] );
- }
- Node lt = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, mkConcat( cc ) );
- conc = NodeManager::currentNM()->mkNode( kind::GEQ, lt, NodeManager::currentNM()->mkConst( Rational(p) ) );
- sendInference( ant, conc, "S-Split(CSP-P)-lprop", true );
- }
- */
}
}
if( !info_valid ){
info.d_ant.push_back( xnz );
- Node const_str = normal_forms[const_k][index];
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, index, index, isRev, info.d_ant );
+ Node const_str = nfcv[index];
+ NormalForm::getExplanationForPrefixEq(
+ nfi, nfj, index, index, info.d_ant);
CVC4::String stra = const_str.getConst<String>();
if( options::stringBinaryCsp() && stra.size()>3 ){
//split string in half
Node c_firstHalf = NodeManager::currentNM()->mkConst( isRev ? stra.substr( stra.size()/2 ) : stra.substr(0, stra.size()/2 ) );
- Node sk = mkSkolemCached( other_str, c_firstHalf , isRev ? sk_id_vc_bin_spt_rev : sk_id_vc_bin_spt, "cb_spt", -1 );
+ Node sk = d_sk_cache.mkSkolemCached(
+ other_str,
+ c_firstHalf,
+ isRev ? SkolemCache::SK_ID_VC_BIN_SPT_REV
+ : SkolemCache::SK_ID_VC_BIN_SPT,
+ "cb_spt");
Trace("strings-csp") << "Const Split: " << c_firstHalf << " is removed from " << const_str << " (binary) " << std::endl;
info.d_conc = NodeManager::currentNM()->mkNode( kind::OR, other_str.eqNode( isRev ? mkConcat( sk, c_firstHalf ) : mkConcat( c_firstHalf, sk ) ),
NodeManager::currentNM()->mkNode( kind::AND,
sk.eqNode( d_emptyString ).negate(),
c_firstHalf.eqNode( isRev ? mkConcat( sk, other_str ) : mkConcat( other_str, sk ) ) ) );
- info.d_new_skolem[0].push_back( sk );
+ info.d_new_skolem[LENGTH_SPLIT].push_back(sk);
info.d_id = INFER_SSPLIT_CST_BINARY;
info_valid = true;
}else{
// normal v/c split
Node firstChar = stra.size() == 1 ? const_str : NodeManager::currentNM()->mkConst( isRev ? stra.suffix( 1 ) : stra.prefix( 1 ) );
- Node sk = mkSkolemCached( other_str, firstChar, isRev ? sk_id_vc_spt_rev : sk_id_vc_spt, "c_spt", -1 );
+ Node sk = d_sk_cache.mkSkolemCached(
+ other_str,
+ firstChar,
+ isRev ? SkolemCache::SK_ID_VC_SPT_REV
+ : SkolemCache::SK_ID_VC_SPT,
+ "c_spt");
Trace("strings-csp") << "Const Split: " << firstChar << " is removed from " << const_str << " (serial) " << std::endl;
info.d_conc = other_str.eqNode( isRev ? mkConcat( sk, firstChar ) : mkConcat(firstChar, sk) );
- info.d_new_skolem[0].push_back( sk );
+ info.d_new_skolem[LENGTH_SPLIT].push_back(sk);
info.d_id = INFER_SSPLIT_CST;
info_valid = true;
}
if( options::stringCheckEntailLen() ){
//check entailment
for( unsigned e=0; e<2; e++ ){
- Node t = e==0 ? normal_forms[i][index] : normal_forms[j][index];
+ Node t = e == 0 ? nfiv[index] : nfjv[index];
//do not infer constants are larger than variables
if( t.getKind()!=kind::CONST_STRING ){
Node lt1 = e==0 ? length_term_i : length_term_j;
}
}
}
-
- getExplanationVectorForPrefixEq( normal_forms, normal_form_src, normal_forms_exp, normal_forms_exp_depend, i, j, index, index, isRev, info.d_ant );
+
+ NormalForm::getExplanationForPrefixEq(
+ nfi, nfj, index, index, info.d_ant);
//x!=e /\ y!=e
for(unsigned xory=0; xory<2; xory++) {
- Node x = xory==0 ? normal_forms[i][index] : normal_forms[j][index];
+ Node x = xory == 0 ? nfiv[index] : nfjv[index];
Node xgtz = x.eqNode( d_emptyString ).negate();
if( d_equalityEngine.areDisequal( x, d_emptyString, true ) ) {
info.d_ant.push_back( xgtz );
info.d_antn.push_back( xgtz );
}
}
- Node sk = mkSkolemCached( normal_forms[i][index], normal_forms[j][index], isRev ? sk_id_v_spt_rev : sk_id_v_spt, "v_spt", -1 );
- //must add length requirement
- info.d_new_skolem[1].push_back( sk );
- Node eq1 = normal_forms[i][index].eqNode( isRev ? mkConcat(sk, normal_forms[j][index]) : mkConcat(normal_forms[j][index], sk) );
- Node eq2 = normal_forms[j][index].eqNode( isRev ? mkConcat(sk, normal_forms[i][index]) : mkConcat(normal_forms[i][index], sk) );
+ Node sk = d_sk_cache.mkSkolemCached(
+ nfiv[index],
+ nfjv[index],
+ isRev ? SkolemCache::SK_ID_V_SPT_REV
+ : SkolemCache::SK_ID_V_SPT,
+ "v_spt");
+ // must add length requirement
+ info.d_new_skolem[LENGTH_GEQ_ONE].push_back(sk);
+ Node eq1 =
+ nfiv[index].eqNode(isRev ? mkConcat(sk, nfjv[index])
+ : mkConcat(nfjv[index], sk));
+ Node eq2 =
+ nfjv[index].eqNode(isRev ? mkConcat(sk, nfiv[index])
+ : mkConcat(nfiv[index], sk));
if( lentTestSuccess!=-1 ){
info.d_antn.push_back( lentTestExp );
}while( success );
}
-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 ){
+bool TheoryStrings::detectLoop(NormalForm& nfi,
+ NormalForm& nfj,
+ int index,
+ int& loop_in_i,
+ int& loop_in_j,
+ unsigned rproc)
+{
int has_loop[2] = { -1, -1 };
if( options::stringLB() != 2 ) {
for( unsigned r=0; r<2; r++ ) {
- int n_index = (r==0 ? i : j);
- int other_n_index = (r==0 ? j : i);
- if( normal_forms[other_n_index][index].getKind() != kind::CONST_STRING ) {
- for( unsigned lp = index+1; lp<normal_forms[n_index].size()-rproc; lp++ ){
- if( normal_forms[n_index][lp]==normal_forms[other_n_index][index] ){
+ NormalForm& nf = r == 0 ? nfi : nfj;
+ NormalForm& nfo = r == 0 ? nfj : nfi;
+ std::vector<Node>& nfv = nf.d_nf;
+ std::vector<Node>& nfov = nfo.d_nf;
+ if (!nfov[index].isConst())
+ {
+ for (unsigned lp = index + 1; lp < nfv.size() - rproc; lp++)
+ {
+ if (nfv[lp] == nfov[index])
+ {
has_loop[r] = lp;
break;
}
}
//xs(zy)=t(yz)xr
-bool TheoryStrings::processLoop( std::vector< std::vector< Node > > &normal_forms, std::vector< Node > &normal_form_src,
- int i, int j, int loop_n_index, int other_n_index, int loop_index, int index, InferInfo& info ){
- if( options::stringAbortLoop() ){
- std::stringstream ss;
- ss << "Looping word equation encountered." << std::endl;
- throw LogicException(ss.str());
- }
- if (!options::stringProcessLoop())
+TheoryStrings::ProcessLoopResult TheoryStrings::processLoop(NormalForm& nfi,
+ NormalForm& nfj,
+ int loop_index,
+ int index,
+ InferInfo& info)
+{
+ if (options::stringProcessLoopMode() == ProcessLoopMode::ABORT)
+ {
+ throw LogicException("Looping word equation encountered.");
+ }
+ else if (options::stringProcessLoopMode() == ProcessLoopMode::NONE)
{
d_out->setIncomplete();
- return false;
+ return ProcessLoopResult::SKIPPED;
}
+
NodeManager* nm = NodeManager::currentNM();
Node conc;
- Trace("strings-loop") << "Detected possible loop for "
- << normal_forms[loop_n_index][loop_index] << std::endl;
- Trace("strings-loop") << " ... (X)= " << normal_forms[other_n_index][index]
- << std::endl;
+ const std::vector<Node>& veci = nfi.d_nf;
+ const std::vector<Node>& vecoi = nfj.d_nf;
+ Trace("strings-loop") << "Detected possible loop for " << veci[loop_index]
+ << std::endl;
+ Trace("strings-loop") << " ... (X)= " << vecoi[index] << std::endl;
Trace("strings-loop") << " ... T(Y.Z)= ";
- std::vector<Node>& veci = normal_forms[loop_n_index];
std::vector<Node> vec_t(veci.begin() + index, veci.begin() + loop_index);
Node t_yz = mkConcat(vec_t);
Trace("strings-loop") << " (" << t_yz << ")" << std::endl;
Trace("strings-loop") << " ... S(Z.Y)= ";
- std::vector<Node>& vecoi = normal_forms[other_n_index];
std::vector<Node> vec_s(vecoi.begin() + index + 1, vecoi.end());
Node s_zy = mkConcat(vec_s);
Trace("strings-loop") << s_zy << std::endl;
Trace("strings-loop") << "Strings::Loop: tails are different."
<< std::endl;
sendInference(info.d_ant, conc, "Loop Conflict", true);
- return false;
+ return ProcessLoopResult::CONFLICT;
}
}
Node split_eq;
for (unsigned r = 0; r < 2; r++)
{
- Node t = r == 0 ? normal_forms[loop_n_index][loop_index] : t_yz;
+ Node t = r == 0 ? veci[loop_index] : t_yz;
split_eq = t.eqNode(d_emptyString);
Node split_eqr = Rewriter::rewrite(split_eq);
// the equality could rewrite to false
// try to make t equal to empty to avoid loop
info.d_conc = nm->mkNode(kind::OR, split_eq, split_eq.negate());
info.d_id = INFER_LEN_SPLIT_EMP;
- return true;
+ return ProcessLoopResult::INFERENCE;
}
else
{
&& s_zy.getConst<String>().isRepeated())
{
Node rep_c = nm->mkConst(s_zy.getConst<String>().substr(0, 1));
- Trace("strings-loop") << "Special case (X)="
- << normal_forms[other_n_index][index] << " "
+ Trace("strings-loop") << "Special case (X)=" << vecoi[index] << " "
<< std::endl;
Trace("strings-loop") << "... (C)=" << rep_c << " " << std::endl;
// special case
- str_in_re =
- nm->mkNode(kind::STRING_IN_REGEXP,
- normal_forms[other_n_index][index],
- nm->mkNode(kind::REGEXP_STAR,
- nm->mkNode(kind::STRING_TO_REGEXP, rep_c)));
+ str_in_re = nm->mkNode(
+ STRING_IN_REGEXP,
+ vecoi[index],
+ nm->mkNode(REGEXP_STAR, nm->mkNode(STRING_TO_REGEXP, rep_c)));
conc = str_in_re;
}
else if (t_yz.isConst())
continue;
}
Node conc2 = nm->mkNode(
- kind::STRING_IN_REGEXP,
- normal_forms[other_n_index][index],
- nm->mkNode(kind::REGEXP_CONCAT,
- nm->mkNode(kind::STRING_TO_REGEXP, y),
- nm->mkNode(kind::REGEXP_STAR,
- nm->mkNode(kind::STRING_TO_REGEXP, restr))));
+ STRING_IN_REGEXP,
+ vecoi[index],
+ nm->mkNode(
+ REGEXP_CONCAT,
+ nm->mkNode(STRING_TO_REGEXP, y),
+ nm->mkNode(REGEXP_STAR, nm->mkNode(STRING_TO_REGEXP, restr))));
cc = cc == d_true ? conc2 : nm->mkNode(kind::AND, cc, conc2);
- d_regexp_ant[conc2] = ant;
vconc.push_back(cc);
}
conc = vconc.size() == 0 ? Node::null() : vconc.size() == 1
}
else
{
+ if (options::stringProcessLoopMode() == ProcessLoopMode::SIMPLE_ABORT)
+ {
+ throw LogicException("Normal looping word equation encountered.");
+ }
+ else if (options::stringProcessLoopMode() == ProcessLoopMode::SIMPLE)
+ {
+ d_out->setIncomplete();
+ return ProcessLoopResult::SKIPPED;
+ }
+
Trace("strings-loop") << "Strings::Loop: Normal Loop Breaking."
<< std::endl;
// right
- Node sk_w = mkSkolemS("w_loop");
- Node sk_y = mkSkolemS("y_loop", 1);
- Node sk_z = mkSkolemS("z_loop");
+ Node sk_w = d_sk_cache.mkSkolem("w_loop");
+ Node sk_y = d_sk_cache.mkSkolem("y_loop");
+ registerLength(sk_y, LENGTH_GEQ_ONE);
+ Node sk_z = d_sk_cache.mkSkolem("z_loop");
// t1 * ... * tn = y * z
Node conc1 = t_yz.eqNode(mkConcat(sk_y, sk_z));
// s1 * ... * sk = z * y * r
vec_r.insert(vec_r.begin(), sk_y);
vec_r.insert(vec_r.begin(), sk_z);
Node conc2 = s_zy.eqNode(mkConcat(vec_r));
- Node conc3 =
- normal_forms[other_n_index][index].eqNode(mkConcat(sk_y, sk_w));
+ Node conc3 = vecoi[index].eqNode(mkConcat(sk_y, sk_w));
Node restr = r == d_emptyString ? s_zy : mkConcat(sk_z, sk_y);
str_in_re =
nm->mkNode(kind::STRING_IN_REGEXP,
conc = nm->mkNode(kind::AND, vec_conc);
} // normal case
- // set its antecedant to ant, to say when it is relevant
- if (!str_in_re.isNull())
- {
- d_regexp_ant[str_in_re] = ant;
- }
// we will be done
info.d_conc = conc;
info.d_id = INFER_FLOOP;
- info.d_nf_pair[0] = normal_form_src[i];
- info.d_nf_pair[1] = normal_form_src[j];
- return true;
+ info.d_nf_pair[0] = nfi.d_base;
+ info.d_nf_pair[1] = nfj.d_base;
+ return ProcessLoopResult::INFERENCE;
}
//return true for lemma, false if we succeed
void TheoryStrings::processDeq( Node ni, Node nj ) {
//Assert( areDisequal( ni, nj ) );
- if( d_normal_forms[ni].size()>1 || d_normal_forms[nj].size()>1 ){
+ NormalForm& nfni = getNormalForm(ni);
+ NormalForm& nfnj = getNormalForm(nj);
+ if (nfni.d_nf.size() > 1 || nfnj.d_nf.size() > 1)
+ {
std::vector< Node > nfi;
- nfi.insert( nfi.end(), d_normal_forms[ni].begin(), d_normal_forms[ni].end() );
+ nfi.insert(nfi.end(), nfni.d_nf.begin(), nfni.d_nf.end());
std::vector< Node > nfj;
- nfj.insert( nfj.end(), d_normal_forms[nj].begin(), d_normal_forms[nj].end() );
+ nfj.insert(nfj.end(), nfnj.d_nf.begin(), nfnj.d_nf.end());
int revRet = processReverseDeq( nfi, nfj, ni, nj );
if( revRet!=0 ){
}
nfi.clear();
- nfi.insert( nfi.end(), d_normal_forms[ni].begin(), d_normal_forms[ni].end() );
+ nfi.insert(nfi.end(), nfni.d_nf.begin(), nfni.d_nf.end());
nfj.clear();
- nfj.insert( nfj.end(), d_normal_forms[nj].begin(), d_normal_forms[nj].end() );
+ nfj.insert(nfj.end(), nfnj.d_nf.begin(), nfnj.d_nf.end());
unsigned index = 0;
while( index<nfi.size() || index<nfj.size() ){
}
}
}else{
- Node sk = mkSkolemCached( nconst_k, firstChar, sk_id_dc_spt, "dc_spt", 2 );
- Node skr = mkSkolemCached( nconst_k, firstChar, sk_id_dc_spt_rem, "dc_spt_rem" );
+ Node sk = d_sk_cache.mkSkolemCached(
+ nconst_k, firstChar, SkolemCache::SK_ID_DC_SPT, "dc_spt");
+ registerLength(sk, LENGTH_ONE);
+ Node skr =
+ d_sk_cache.mkSkolemCached(nconst_k,
+ firstChar,
+ SkolemCache::SK_ID_DC_SPT_REM,
+ "dc_spt_rem");
Node eq1 = nconst_k.eqNode( NodeManager::currentNM()->mkNode( kind::STRING_CONCAT, sk, skr ) );
eq1 = Rewriter::rewrite( eq1 );
Node eq2 = nconst_k.eqNode( NodeManager::currentNM()->mkNode( kind::STRING_CONCAT, firstChar, skr ) );
std::vector< Node > antec;
- antec.insert( antec.end(), d_normal_forms_exp[ni].begin(), d_normal_forms_exp[ni].end() );
- antec.insert( antec.end(), d_normal_forms_exp[nj].begin(), d_normal_forms_exp[nj].end() );
+ antec.insert(
+ antec.end(), nfni.d_exp.begin(), nfni.d_exp.end());
+ antec.insert(
+ antec.end(), nfnj.d_exp.begin(), nfnj.d_exp.end());
antec.push_back( nconst_k.eqNode( d_emptyString ).negate() );
sendInference( antec, NodeManager::currentNM()->mkNode( kind::OR,
NodeManager::currentNM()->mkNode( kind::AND, eq1, sk.eqNode( firstChar ).negate() ), eq2 ), "D-DISL-CSplit" );
//must add lemma
std::vector< Node > antec;
std::vector< Node > antec_new_lits;
- antec.insert( antec.end(), d_normal_forms_exp[ni].begin(), d_normal_forms_exp[ni].end() );
- antec.insert( antec.end(), d_normal_forms_exp[nj].begin(), d_normal_forms_exp[nj].end() );
+ antec.insert(antec.end(), nfni.d_exp.begin(), nfni.d_exp.end());
+ antec.insert(antec.end(), nfnj.d_exp.begin(), nfnj.d_exp.end());
//check disequal
if( areDisequal( ni, nj ) ){
antec.push_back( ni.eqNode( nj ).negate() );
}
antec_new_lits.push_back( li.eqNode( lj ).negate() );
std::vector< Node > conc;
- Node sk1 = mkSkolemCached( i, j, sk_id_deq_x, "x_dsplit" );
- Node sk2 = mkSkolemCached( i, j, sk_id_deq_y, "y_dsplit" );
- Node sk3 = mkSkolemCached( i, j, sk_id_deq_z, "z_dsplit", 1 );
+ Node sk1 = d_sk_cache.mkSkolemCached(
+ i, j, SkolemCache::SK_ID_DEQ_X, "x_dsplit");
+ Node sk2 = d_sk_cache.mkSkolemCached(
+ i, j, SkolemCache::SK_ID_DEQ_Y, "y_dsplit");
+ Node sk3 = d_sk_cache.mkSkolemCached(
+ i, j, SkolemCache::SK_ID_DEQ_Z, "z_dsplit");
+ registerLength(sk3, LENGTH_GEQ_ONE);
//Node nemp = sk3.eqNode(d_emptyString).negate();
//conc.push_back(nemp);
Node lsk1 = mkLength( sk1 );
}
}
}
+ NormalForm& nfni = getNormalForm(ni);
+ NormalForm& nfnj = getNormalForm(nj);
while( index<nfi.size() || index<nfj.size() ) {
if( index>=nfi.size() || index>=nfj.size() ){
Trace("strings-solve-debug") << "Disequality normalize empty" << std::endl;
std::vector< Node > ant;
//we have a conflict : because the lengths are equal, the remainder needs to be empty, which will lead to a conflict
- Node lni = getLengthExp( ni, ant, d_normal_forms_base[ni] );
- Node lnj = getLengthExp( nj, ant, d_normal_forms_base[nj] );
+ Node lni = getLengthExp(ni, ant, nfni.d_base);
+ Node lnj = getLengthExp(nj, ant, nfnj.d_base);
ant.push_back( lni.eqNode( lnj ) );
- ant.insert( ant.end(), d_normal_forms_exp[ni].begin(), d_normal_forms_exp[ni].end() );
- ant.insert( ant.end(), d_normal_forms_exp[nj].begin(), d_normal_forms_exp[nj].end() );
+ ant.insert(ant.end(), nfni.d_exp.begin(), nfni.d_exp.end());
+ ant.insert(ant.end(), nfnj.d_exp.begin(), nfnj.d_exp.end());
std::vector< Node > cc;
std::vector< Node >& nfk = index>=nfi.size() ? nfj : nfi;
for( unsigned index_k=index; index_k<nfk.size(); index_k++ ){
}
else
{
- do_register = effort > 0 || n.getKind() != kind::STRING_CONCAT;
+ do_register = effort > 0 || n.getKind() != STRING_CONCAT;
}
}
- if( do_register ){
- if(d_registered_terms_cache.find(n) == d_registered_terms_cache.end()) {
- d_registered_terms_cache.insert(n);
- Debug("strings-register") << "TheoryStrings::registerTerm() " << n << ", effort = " << effort << std::endl;
- if (tn.isString())
+ if (!do_register)
+ {
+ return;
+ }
+ if (d_registered_terms_cache.find(n) != d_registered_terms_cache.end())
+ {
+ return;
+ }
+ d_registered_terms_cache.insert(n);
+ NodeManager* nm = NodeManager::currentNM();
+ Debug("strings-register") << "TheoryStrings::registerTerm() " << n
+ << ", effort = " << effort << std::endl;
+ if (tn.isString())
+ {
+ // register length information:
+ // for variables, split on empty vs positive length
+ // for concat/const/replace, introduce proxy var and state length relation
+ Node lsum;
+ if (n.getKind() != STRING_CONCAT && n.getKind() != CONST_STRING)
+ {
+ Node lsumb = nm->mkNode(STRING_LENGTH, n);
+ lsum = Rewriter::rewrite(lsumb);
+ // can register length term if it does not rewrite
+ if (lsum == lsumb)
{
- //register length information:
- // for variables, split on empty vs positive length
- // for concat/const/replace, introduce proxy var and state length relation
- Node lsum;
- bool processed = false;
- if( n.getKind()!=kind::STRING_CONCAT && n.getKind()!=kind::CONST_STRING ) {
- if( d_length_lemma_terms_cache.find( n )==d_length_lemma_terms_cache.end() ){
- Node lsumb = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, n );
- lsum = Rewriter::rewrite( lsumb );
- // can register length term if it does not rewrite
- if( lsum==lsumb ){
- sendLengthLemma( n );
- processed = true;
- }
- }else{
- processed = true;
- }
+ registerLength(n, LENGTH_SPLIT);
+ return;
+ }
+ }
+ Node sk = d_sk_cache.mkSkolemCached(n, SkolemCache::SK_PURIFY, "lsym");
+ StringsProxyVarAttribute spva;
+ sk.setAttribute(spva, true);
+ Node eq = Rewriter::rewrite(sk.eqNode(n));
+ Trace("strings-lemma") << "Strings::Lemma LENGTH Term : " << eq
+ << std::endl;
+ d_proxy_var[n] = sk;
+ // If we are introducing a proxy for a constant or concat term, we do not
+ // need to send lemmas about its length, since its length is already
+ // implied.
+ if (n.isConst() || n.getKind() == STRING_CONCAT)
+ {
+ // add to length lemma cache, i.e. do not send length lemma for sk.
+ d_length_lemma_terms_cache.insert(sk);
+ }
+ Trace("strings-assert") << "(assert " << eq << ")" << std::endl;
+ d_out->lemma(eq);
+ Node skl = nm->mkNode(STRING_LENGTH, sk);
+ if (n.getKind() == STRING_CONCAT)
+ {
+ std::vector<Node> node_vec;
+ for (unsigned i = 0; i < n.getNumChildren(); i++)
+ {
+ if (n[i].getAttribute(StringsProxyVarAttribute()))
+ {
+ Assert(d_proxy_var_to_length.find(n[i])
+ != d_proxy_var_to_length.end());
+ node_vec.push_back(d_proxy_var_to_length[n[i]]);
}
- if( !processed ){
- Node sk = mkSkolemS( "lsym", -1 );
- StringsProxyVarAttribute spva;
- sk.setAttribute(spva,true);
- Node eq = Rewriter::rewrite( sk.eqNode(n) );
- Trace("strings-lemma") << "Strings::Lemma LENGTH Term : " << eq << std::endl;
- d_proxy_var[n] = sk;
- Trace("strings-assert") << "(assert " << eq << ")" << std::endl;
- d_out->lemma(eq);
- Node skl = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, sk );
- if( n.getKind()==kind::STRING_CONCAT ){
- std::vector<Node> node_vec;
- for( unsigned i=0; i<n.getNumChildren(); i++ ) {
- if( n[i].getAttribute(StringsProxyVarAttribute()) ){
- Assert( d_proxy_var_to_length.find( n[i] )!=d_proxy_var_to_length.end() );
- node_vec.push_back( d_proxy_var_to_length[n[i]] );
- }else{
- Node lni = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, n[i] );
- node_vec.push_back(lni);
- }
- }
- lsum = NodeManager::currentNM()->mkNode( kind::PLUS, node_vec );
- lsum = Rewriter::rewrite( lsum );
- }else if( n.getKind()==kind::CONST_STRING ){
- lsum = NodeManager::currentNM()->mkConst( ::CVC4::Rational( n.getConst<String>().size() ) );
- }
- Assert( !lsum.isNull() );
- d_proxy_var_to_length[sk] = lsum;
- Node ceq = Rewriter::rewrite( skl.eqNode( lsum ) );
- Trace("strings-lemma") << "Strings::Lemma LENGTH : " << ceq << std::endl;
- Trace("strings-lemma-debug") << " prerewrite : " << skl.eqNode( lsum ) << std::endl;
- Trace("strings-assert") << "(assert " << ceq << ")" << std::endl;
- d_out->lemma(ceq);
+ else
+ {
+ Node lni = nm->mkNode(STRING_LENGTH, n[i]);
+ node_vec.push_back(lni);
}
}
- else if (n.getKind() == kind::STRING_CODE)
+ lsum = nm->mkNode(PLUS, node_vec);
+ lsum = Rewriter::rewrite(lsum);
+ }
+ else if (n.getKind() == CONST_STRING)
+ {
+ lsum = nm->mkConst(Rational(n.getConst<String>().size()));
+ }
+ Assert(!lsum.isNull());
+ d_proxy_var_to_length[sk] = lsum;
+ Node ceq = Rewriter::rewrite(skl.eqNode(lsum));
+ Trace("strings-lemma") << "Strings::Lemma LENGTH : " << ceq << std::endl;
+ Trace("strings-lemma-debug")
+ << " prerewrite : " << skl.eqNode(lsum) << std::endl;
+ Trace("strings-assert") << "(assert " << ceq << ")" << std::endl;
+ d_out->lemma(ceq);
+ }
+ else if (n.getKind() == STRING_CODE)
+ {
+ d_has_str_code = true;
+ // ite( str.len(s)==1, 0 <= str.code(s) < num_codes, str.code(s)=-1 )
+ Node code_len = mkLength(n[0]).eqNode(d_one);
+ Node code_eq_neg1 = n.eqNode(d_neg_one);
+ Node code_range = nm->mkNode(
+ AND,
+ nm->mkNode(GEQ, n, d_zero),
+ nm->mkNode(LT, n, nm->mkConst(Rational(CVC4::String::num_codes()))));
+ Node lem = nm->mkNode(ITE, code_len, code_range, code_eq_neg1);
+ Trace("strings-lemma") << "Strings::Lemma CODE : " << lem << std::endl;
+ Trace("strings-assert") << "(assert " << lem << ")" << std::endl;
+ d_out->lemma(lem);
+ }
+}
+
+bool TheoryStrings::sendInternalInference(std::vector<Node>& exp,
+ Node conc,
+ const char* c)
+{
+ if (conc.getKind() == AND
+ || (conc.getKind() == NOT && conc[0].getKind() == OR))
+ {
+ Node conj = conc.getKind() == AND ? conc : conc[0];
+ bool pol = conc.getKind() == AND;
+ bool ret = true;
+ for (const Node& cc : conj)
+ {
+ bool retc = sendInternalInference(exp, pol ? cc : cc.negate(), c);
+ ret = ret && retc;
+ }
+ return ret;
+ }
+ bool pol = conc.getKind() != NOT;
+ Node lit = pol ? conc : conc[0];
+ if (lit.getKind() == EQUAL)
+ {
+ for (unsigned i = 0; i < 2; i++)
+ {
+ if (!lit[i].isConst() && !hasTerm(lit[i]))
{
- d_has_str_code = true;
- NodeManager* nm = NodeManager::currentNM();
- // ite( str.len(s)==1, 0 <= str.code(s) < num_codes, str.code(s)=-1 )
- Node code_len = mkLength(n[0]).eqNode(d_one);
- Node code_eq_neg1 = n.eqNode(d_neg_one);
- Node code_range = nm->mkNode(
- kind::AND,
- nm->mkNode(kind::GEQ, n, d_zero),
- nm->mkNode(
- kind::LT, n, nm->mkConst(Rational(CVC4::String::num_codes()))));
- Node lem = nm->mkNode(kind::ITE, code_len, code_range, code_eq_neg1);
- Trace("strings-lemma") << "Strings::Lemma CODE : " << lem << std::endl;
- Trace("strings-assert") << "(assert " << lem << ")" << std::endl;
- d_out->lemma(lem);
+ // introduces a new non-constant term, do not infer
+ return false;
}
}
+ // does it already hold?
+ if (pol ? areEqual(lit[0], lit[1]) : areDisequal(lit[0], lit[1]))
+ {
+ return true;
+ }
}
+ else if (lit.isConst())
+ {
+ if (lit.getConst<bool>())
+ {
+ Assert(pol);
+ // trivially holds
+ return true;
+ }
+ }
+ else if (!hasTerm(lit))
+ {
+ // introduces a new non-constant term, do not infer
+ return false;
+ }
+ else if (areEqual(lit, pol ? d_true : d_false))
+ {
+ // already holds
+ return true;
+ }
+ sendInference(exp, conc, c);
+ return true;
}
void TheoryStrings::sendInference( std::vector< Node >& exp, std::vector< Node >& exp_n, Node eq, const char * c, bool asLemma ) {
return false;
}
+void TheoryStrings::registerLength(Node n, LengthStatus s)
+{
+ if (d_length_lemma_terms_cache.find(n) != d_length_lemma_terms_cache.end())
+ {
+ return;
+ }
+ d_length_lemma_terms_cache.insert(n);
+
+ NodeManager* nm = NodeManager::currentNM();
+ Node n_len = nm->mkNode(kind::STRING_LENGTH, n);
+
+ if (s == LENGTH_GEQ_ONE)
+ {
+ Node neq_empty = n.eqNode(d_emptyString).negate();
+ Node len_n_gt_z = nm->mkNode(GT, n_len, d_zero);
+ Node len_geq_one = nm->mkNode(AND, neq_empty, len_n_gt_z);
+ Trace("strings-lemma") << "Strings::Lemma SK-GEQ-ONE : " << len_geq_one
+ << std::endl;
+ Trace("strings-assert") << "(assert " << len_geq_one << ")" << std::endl;
+ d_out->lemma(len_geq_one);
+ return;
+ }
+
+ if (s == LENGTH_ONE)
+ {
+ Node len_one = n_len.eqNode(d_one);
+ Trace("strings-lemma") << "Strings::Lemma SK-ONE : " << len_one
+ << std::endl;
+ Trace("strings-assert") << "(assert " << len_one << ")" << std::endl;
+ d_out->lemma(len_one);
+ return;
+ }
+ Assert(s == LENGTH_SPLIT);
-void TheoryStrings::sendLengthLemma( Node n ){
- Node n_len = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, n);
if( options::stringSplitEmp() || !options::stringLenGeqZ() ){
- NodeManager* nm = NodeManager::currentNM();
Node n_len_eq_z = n_len.eqNode( d_zero );
Node n_len_eq_z_2 = n.eqNode( d_emptyString );
Node case_empty = nm->mkNode(AND, n_len_eq_z, n_len_eq_z_2);
Assert(false);
}
}
- //AJR: probably a good idea
+
+ // additionally add len( x ) >= 0 ?
if( options::stringLenGeqZ() ){
- Node n_len_geq = NodeManager::currentNM()->mkNode( kind::GEQ, n_len, d_zero);
+ Node n_len_geq = nm->mkNode(kind::GEQ, n_len, d_zero);
n_len_geq = Rewriter::rewrite( n_len_geq );
d_out->lemma( n_len_geq );
}
return Rewriter::rewrite( NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, t ) );
}
-Node TheoryStrings::mkSkolemCached( Node a, Node b, int id, const char * c, int isLenSplit ){
- //return mkSkolemS( c, isLenSplit );
- std::map< int, Node >::iterator it = d_skolem_cache[a][b].find( id );
- if( it==d_skolem_cache[a][b].end() ){
- Node sk = mkSkolemS( c, isLenSplit );
- d_skolem_cache[a][b][id] = sk;
- return sk;
- }else{
- return it->second;
- }
-}
-
-//isLenSplit: -1-ignore, 0-no restriction, 1-greater than one, 2-one
-Node TheoryStrings::mkSkolemS( const char *c, int isLenSplit ) {
- Node n = NodeManager::currentNM()->mkSkolem( c, NodeManager::currentNM()->stringType(), "string sko" );
- d_all_skolems.insert(n);
- d_length_lemma_terms_cache.insert( n );
- ++(d_statistics.d_new_skolems);
- if( isLenSplit==0 ){
- sendLengthLemma( n );
- } else if( isLenSplit == 1 ){
- registerNonEmptySkolem( n );
- }else if( isLenSplit==2 ){
- Node len_one = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, n ).eqNode( d_one );
- Trace("strings-lemma") << "Strings::Lemma SK-ONE : " << len_one << std::endl;
- Trace("strings-assert") << "(assert " << len_one << ")" << std::endl;
- d_out->lemma( len_one );
- }
- return n;
-}
-
-void TheoryStrings::registerNonEmptySkolem( Node n ) {
- if( d_skolem_ne_reg_cache.find( n )==d_skolem_ne_reg_cache.end() ){
- d_skolem_ne_reg_cache.insert( n );
- d_equalityEngine.assertEquality(n.eqNode(d_emptyString), false, d_true);
- Node len_n_gt_z = NodeManager::currentNM()->mkNode(kind::GT,
- NodeManager::currentNM()->mkNode(kind::STRING_LENGTH, n), d_zero);
- Trace("strings-lemma") << "Strings::Lemma SK-NON-ZERO : " << len_n_gt_z << std::endl;
- Trace("strings-assert") << "(assert " << len_n_gt_z << ")" << std::endl;
- d_out->lemma(len_n_gt_z);
- }
-}
-
Node TheoryStrings::mkExplain( std::vector< Node >& a ) {
std::vector< Node > an;
return mkExplain( a, an );
}
}
-void TheoryStrings::getConcatVec( Node n, std::vector< Node >& c ) {
- if( n.getKind()==kind::STRING_CONCAT ) {
- for( unsigned i=0; i<n.getNumChildren(); i++ ) {
- if( !areEqual( n[i], d_emptyString ) ) {
- c.push_back( n[i] );
- }
- }
- }else{
- c.push_back( n );
- }
-}
-
void TheoryStrings::checkNormalFormsDeq()
{
std::vector< std::vector< Node > > cols;
separateByLength( d_strings_eqc, cols, lts );
for( unsigned i=0; i<cols.size(); i++ ){
if( cols[i].size()>1 && d_lemma_cache.empty() ){
- Trace("strings-solve") << "- Verify disequalities are processed for " << cols[i][0] << ", normal form : ";
- printConcat( d_normal_forms[cols[i][0]], "strings-solve" );
- Trace("strings-solve") << "... #eql = " << cols[i].size() << std::endl;
+ if (Trace.isOn("strings-solve"))
+ {
+ Trace("strings-solve") << "- Verify disequalities are processed for "
+ << cols[i][0] << ", normal form : ";
+ printConcat(getNormalForm(cols[i][0]).d_nf, "strings-solve");
+ Trace("strings-solve")
+ << "... #eql = " << cols[i].size() << std::endl;
+ }
//must ensure that normal forms are disequal
for( unsigned j=0; j<cols[i].size(); j++ ){
for( unsigned k=(j+1); k<cols[i].size(); k++ ){
//for strings that are disequal, but have the same length
- if( areDisequal( cols[i][j], cols[i][k] ) ){
- Assert( !d_conflict );
- Trace("strings-solve") << "- Compare " << cols[i][j] << " ";
- printConcat( d_normal_forms[cols[i][j]], "strings-solve" );
- Trace("strings-solve") << " against " << cols[i][k] << " ";
- printConcat( d_normal_forms[cols[i][k]], "strings-solve" );
- Trace("strings-solve") << "..." << std::endl;
- processDeq( cols[i][j], cols[i][k] );
- if( hasProcessed() ){
- return;
+ if (cols[i][j].isConst() && cols[i][k].isConst())
+ {
+ // if both are constants, they should be distinct, and its trivial
+ Assert(cols[i][j] != cols[i][k]);
+ }
+ else
+ {
+ if (areDisequal(cols[i][j], cols[i][k]))
+ {
+ Assert(!d_conflict);
+ if (Trace.isOn("strings-solve"))
+ {
+ Trace("strings-solve") << "- Compare " << cols[i][j] << " ";
+ printConcat(getNormalForm(cols[i][j]).d_nf, "strings-solve");
+ Trace("strings-solve") << " against " << cols[i][k] << " ";
+ printConcat(getNormalForm(cols[i][k]).d_nf, "strings-solve");
+ Trace("strings-solve") << "..." << std::endl;
+ }
+ processDeq(cols[i][j], cols[i][k]);
+ if (hasProcessed())
+ {
+ return;
+ }
}
}
}
void TheoryStrings::checkLengthsEqc() {
if( options::stringLenNorm() ){
for( unsigned i=0; i<d_strings_eqc.size(); i++ ){
- //if( d_normal_forms[nodes[i]].size()>1 ) {
+ NormalForm& nfi = getNormalForm(d_strings_eqc[i]);
Trace("strings-process-debug") << "Process length constraints for " << d_strings_eqc[i] << std::endl;
//check if there is a length term for this equivalence class
EqcInfo* ei = getOrMakeEqcInfo( d_strings_eqc[i], false );
Node llt = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, lt );
//now, check if length normalization has occurred
if( ei->d_normalized_length.get().isNull() ) {
- Node nf = mkConcat( d_normal_forms[d_strings_eqc[i]] );
+ Node nf = mkConcat(nfi.d_nf);
if( Trace.isOn("strings-process-debug") ){
- Trace("strings-process-debug") << " normal form is " << nf << " from base " << d_normal_forms_base[d_strings_eqc[i]] << std::endl;
+ Trace("strings-process-debug")
+ << " normal form is " << nf << " from base " << nfi.d_base
+ << std::endl;
Trace("strings-process-debug") << " normal form exp is: " << std::endl;
- for( unsigned j=0; j<d_normal_forms_exp[d_strings_eqc[i]].size(); j++ ){
- Trace("strings-process-debug") << " " << d_normal_forms_exp[d_strings_eqc[i]][j] << std::endl;
+ for (const Node& exp : nfi.d_exp)
+ {
+ Trace("strings-process-debug") << " " << exp << std::endl;
}
}
//if not, add the lemma
std::vector< Node > ant;
- ant.insert( ant.end(), d_normal_forms_exp[d_strings_eqc[i]].begin(), d_normal_forms_exp[d_strings_eqc[i]].end() );
- ant.push_back( d_normal_forms_base[d_strings_eqc[i]].eqNode( lt ) );
+ ant.insert(ant.end(), nfi.d_exp.begin(), nfi.d_exp.end());
+ ant.push_back(nfi.d_base.eqNode(lt));
Node lc = NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, nf );
Node lcr = Rewriter::rewrite( lc );
Trace("strings-process-debug") << "Rewrote length " << lc << " to " << lcr << std::endl;
- Node eq = llt.eqNode( lcr );
- if( llt!=lcr ){
+ if (!areEqual(llt, lcr))
+ {
+ Node eq = llt.eqNode(lcr);
ei->d_normalized_length.set( eq );
sendInference( ant, eq, "LEN-NORM", true );
}
}else{
Trace("strings-process-debug") << "No length term for eqc " << d_strings_eqc[i] << " " << d_eqc_to_len_term[d_strings_eqc[i]] << std::endl;
if( !options::stringEagerLen() ){
- Node c = mkConcat( d_normal_forms[d_strings_eqc[i]] );
+ Node c = mkConcat(nfi.d_nf);
registerTerm( c, 3 );
/*
if( !c.isConst() ){
std::vector< Node > lts;
separateByLength( d_strings_eqc, cols, lts );
+ Trace("strings-card") << "Check cardinality...." << std::endl;
for( unsigned i = 0; i<cols.size(); ++i ) {
Node lr = lts[i];
Trace("strings-card") << "Number of strings with length equal to " << lr << " is " << cols[i].size() << std::endl;
}
}
}
+ Trace("strings-card") << "...end check cardinality" << std::endl;
}
void TheoryStrings::getEquivalenceClasses( std::vector< Node >& eqcs ) {
}
-
//// Finite Model Finding
-Node TheoryStrings::getNextDecisionRequest( unsigned& priority ) {
- if( options::stringFMF() && !d_conflict ){
- Node in_var_lsum = d_input_var_lsum.get();
- //Trace("strings-fmf-debug") << "Strings::FMF: Assertion Level = " << d_valuation.getAssertionLevel() << std::endl;
- //initialize the term we will minimize
- if( in_var_lsum.isNull() && !d_input_vars.empty() ){
- Trace("strings-fmf-debug") << "Input variables: ";
- std::vector< Node > ll;
- for(NodeSet::key_iterator itr = d_input_vars.key_begin();
- itr != d_input_vars.key_end(); ++itr) {
- Trace("strings-fmf-debug") << " " << (*itr) ;
- ll.push_back( NodeManager::currentNM()->mkNode( kind::STRING_LENGTH, *itr ) );
- }
- Trace("strings-fmf-debug") << std::endl;
- in_var_lsum = ll.size()==1 ? ll[0] : NodeManager::currentNM()->mkNode( kind::PLUS, ll );
- in_var_lsum = Rewriter::rewrite( in_var_lsum );
- d_input_var_lsum.set( in_var_lsum );
- }
- if( !in_var_lsum.isNull() ){
- //Trace("strings-fmf") << "Get next decision request." << std::endl;
- //check if we need to decide on something
- int decideCard = d_curr_cardinality.get();
- if( d_cardinality_lits.find( decideCard )!=d_cardinality_lits.end() ){
- bool value;
- Node cnode = d_cardinality_lits[ d_curr_cardinality.get() ];
- if( d_valuation.hasSatValue( cnode, value ) ) {
- if( !value ){
- d_curr_cardinality.set( d_curr_cardinality.get() + 1 );
- decideCard = d_curr_cardinality.get();
- Trace("strings-fmf-debug") << "Has false SAT value, increment and decide." << std::endl;
- }else{
- decideCard = -1;
- Trace("strings-fmf-debug") << "Has true SAT value, do not decide." << std::endl;
- }
- }else{
- Trace("strings-fmf-debug") << "No SAT value, decide." << std::endl;
- }
- }
- if( decideCard!=-1 ){
- if( d_cardinality_lits.find( decideCard )==d_cardinality_lits.end() ){
- Node lit = NodeManager::currentNM()->mkNode( kind::LEQ, in_var_lsum, NodeManager::currentNM()->mkConst( Rational( decideCard ) ) );
- lit = Rewriter::rewrite( lit );
- d_cardinality_lits[decideCard] = lit;
- Node lem = NodeManager::currentNM()->mkNode( kind::OR, lit, lit.negate() );
- Trace("strings-fmf") << "Strings::FMF: Add decision lemma " << lem << ", decideCard = " << decideCard << std::endl;
- d_out->lemma( lem );
- d_out->requirePhase( lit, true );
- }
- Node lit = d_cardinality_lits[ decideCard ];
- Trace("strings-fmf") << "Strings::FMF: Decide positive on " << lit << std::endl;
- priority = 1;
- return lit;
- }
+TheoryStrings::StringSumLengthDecisionStrategy::StringSumLengthDecisionStrategy(
+ context::Context* c, context::UserContext* u, Valuation valuation)
+ : DecisionStrategyFmf(c, valuation), d_input_var_lsum(u)
+{
+}
+
+bool TheoryStrings::StringSumLengthDecisionStrategy::isInitialized()
+{
+ return !d_input_var_lsum.get().isNull();
+}
+
+void TheoryStrings::StringSumLengthDecisionStrategy::initialize(
+ const std::vector<Node>& vars)
+{
+ if (d_input_var_lsum.get().isNull() && !vars.empty())
+ {
+ NodeManager* nm = NodeManager::currentNM();
+ std::vector<Node> sum;
+ for (const Node& v : vars)
+ {
+ sum.push_back(nm->mkNode(STRING_LENGTH, v));
}
+ Node sumn = sum.size() == 1 ? sum[0] : nm->mkNode(PLUS, sum);
+ d_input_var_lsum.set(sumn);
}
- return Node::null();
+}
+
+Node TheoryStrings::StringSumLengthDecisionStrategy::mkLiteral(unsigned i)
+{
+ if (d_input_var_lsum.get().isNull())
+ {
+ return Node::null();
+ }
+ NodeManager* nm = NodeManager::currentNM();
+ Node lit = nm->mkNode(LEQ, d_input_var_lsum.get(), nm->mkConst(Rational(i)));
+ Trace("strings-fmf") << "StringsFMF::mkLiteral: " << lit << std::endl;
+ return lit;
+}
+std::string TheoryStrings::StringSumLengthDecisionStrategy::identify() const
+{
+ return std::string("string_sum_len");
}
Node TheoryStrings::ppRewrite(TNode atom) {
}
// Stats
-TheoryStrings::Statistics::Statistics():
- d_splits("theory::strings::NumOfSplitOnDemands", 0),
- d_eq_splits("theory::strings::NumOfEqSplits", 0),
- d_deq_splits("theory::strings::NumOfDiseqSplits", 0),
- d_loop_lemmas("theory::strings::NumOfLoops", 0),
- d_new_skolems("theory::strings::NumOfNewSkolems", 0)
+TheoryStrings::Statistics::Statistics()
+ : d_splits("theory::strings::NumOfSplitOnDemands", 0),
+ d_eq_splits("theory::strings::NumOfEqSplits", 0),
+ d_deq_splits("theory::strings::NumOfDiseqSplits", 0),
+ d_loop_lemmas("theory::strings::NumOfLoops", 0)
{
smtStatisticsRegistry()->registerStat(&d_splits);
smtStatisticsRegistry()->registerStat(&d_eq_splits);
smtStatisticsRegistry()->registerStat(&d_deq_splits);
smtStatisticsRegistry()->registerStat(&d_loop_lemmas);
- smtStatisticsRegistry()->registerStat(&d_new_skolems);
}
TheoryStrings::Statistics::~Statistics(){
smtStatisticsRegistry()->unregisterStat(&d_eq_splits);
smtStatisticsRegistry()->unregisterStat(&d_deq_splits);
smtStatisticsRegistry()->unregisterStat(&d_loop_lemmas);
- smtStatisticsRegistry()->unregisterStat(&d_new_skolems);
-}
-
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-
-//// Regular Expressions
-
-
-unsigned TheoryStrings::getNumMemberships( Node n, bool isPos ) {
- if( isPos ){
- NodeIntMap::const_iterator it = d_pos_memberships.find( n );
- if( it!=d_pos_memberships.end() ){
- return (*it).second;
- }
- }else{
- NodeIntMap::const_iterator it = d_neg_memberships.find( n );
- if( it!=d_neg_memberships.end() ){
- return (*it).second;
- }
- }
- return 0;
-}
-
-Node TheoryStrings::getMembership( Node n, bool isPos, unsigned i ) {
- return isPos ? d_pos_memberships_data[n][i] : d_neg_memberships_data[n][i];
-}
-
-Node TheoryStrings::mkRegExpAntec(Node atom, Node ant) {
- if(d_regexp_ant.find(atom) == d_regexp_ant.end()) {
- return NodeManager::currentNM()->mkNode(kind::AND, ant, atom);
- } else {
- Node n = d_regexp_ant[atom];
- return NodeManager::currentNM()->mkNode(kind::AND, ant, n);
- }
-}
-
-void TheoryStrings::checkMemberships() {
- //add the memberships
- std::vector<Node> mems = getExtTheory()->getActive(kind::STRING_IN_REGEXP);
- for (unsigned i = 0; i < mems.size(); i++) {
- Node n = mems[i];
- Assert( d_extf_info_tmp.find( n )!=d_extf_info_tmp.end() );
- if( d_extf_info_tmp[n].d_pol==1 || d_extf_info_tmp[n].d_pol==-1 ){
- bool pol = d_extf_info_tmp[n].d_pol==1;
- Trace("strings-process-debug") << " add membership : " << n << ", pol = " << pol << std::endl;
- addMembership( pol ? n : n.negate() );
- }else{
- Trace("strings-process-debug") << " irrelevant (non-asserted) membership : " << n << std::endl;
- }
- }
-
- bool addedLemma = false;
- bool changed = false;
- std::vector< Node > processed;
- std::vector< Node > cprocessed;
-
- Trace("regexp-debug") << "Checking Memberships ... " << std::endl;
- //if(options::stringEIT()) {
- //TODO: Opt for normal forms
- for( NodeIntMap::const_iterator itr_xr = d_pos_memberships.begin(); itr_xr != d_pos_memberships.end(); ++itr_xr ){
- bool spflag = false;
- Node x = (*itr_xr).first;
- Trace("regexp-debug") << "Checking Memberships for " << x << std::endl;
- if(d_inter_index.find(x) == d_inter_index.end()) {
- d_inter_index[x] = 0;
- }
- int cur_inter_idx = d_inter_index[x];
- unsigned n_pmem = (*itr_xr).second;
- Assert( getNumMemberships( x, true )==n_pmem );
- if( cur_inter_idx != (int)n_pmem ) {
- if( n_pmem == 1) {
- d_inter_cache[x] = getMembership( x, true, 0 );
- d_inter_index[x] = 1;
- Trace("regexp-debug") << "... only one choice " << std::endl;
- } else if(n_pmem > 1) {
- Node r;
- if(d_inter_cache.find(x) != d_inter_cache.end()) {
- r = d_inter_cache[x];
- }
- if(r.isNull()) {
- r = getMembership( x, true, 0 );
- cur_inter_idx = 1;
- }
-
- unsigned k_start = cur_inter_idx;
- Trace("regexp-debug") << "... staring from : " << cur_inter_idx << ", we have " << n_pmem << std::endl;
- for(unsigned k = k_start; k<n_pmem; k++) {
- Node r2 = getMembership( x, true, k );
- r = d_regexp_opr.intersect(r, r2, spflag);
- if(spflag) {
- break;
- } else if(r == d_emptyRegexp) {
- std::vector< Node > vec_nodes;
- for( unsigned kk=0; kk<=k; kk++ ){
- Node rr = getMembership( x, true, kk );
- Node n = NodeManager::currentNM()->mkNode(kind::STRING_IN_REGEXP, x, rr);
- vec_nodes.push_back( n );
- }
- Node conc;
- sendInference(vec_nodes, conc, "INTERSECT CONFLICT", true);
- addedLemma = true;
- break;
- }
- if(d_conflict) {
- break;
- }
- }
- //updates
- if(!d_conflict && !spflag) {
- d_inter_cache[x] = r;
- d_inter_index[x] = (int)n_pmem;
- }
- }
- }
- }
- //}
-
- Trace("regexp-debug") << "... No Intersect Conflict in Memberships, addedLemma: " << addedLemma << std::endl;
- if(!addedLemma) {
- NodeManager* nm = NodeManager::currentNM();
- for( unsigned i=0; i<d_regexp_memberships.size(); i++ ) {
- //check regular expression membership
- Node assertion = d_regexp_memberships[i];
- 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;
- if( d_regexp_ucached.find(assertion) == d_regexp_ucached.end()
- && d_regexp_ccached.find(assertion) == d_regexp_ccached.end() ) {
- Trace("strings-regexp") << "We have regular expression assertion : " << assertion << std::endl;
- Node atom = assertion.getKind()==kind::NOT ? assertion[0] : assertion;
- bool polarity = assertion.getKind()!=kind::NOT;
- bool flag = true;
- Node x = atom[0];
- Node r = atom[1];
- std::vector< Node > rnfexp;
-
- if (!x.isConst())
- {
- x = getNormalString(x, rnfexp);
- changed = true;
- }
- if (!d_regexp_opr.checkConstRegExp(r))
- {
- r = getNormalSymRegExp(r, rnfexp);
- changed = true;
- }
- Trace("strings-regexp-nf") << "Term " << atom << " is normalized to "
- << x << " IN " << r << std::endl;
- if (changed)
- {
- Node tmp =
- Rewriter::rewrite(nm->mkNode(kind::STRING_IN_REGEXP, x, r));
- if (!polarity)
- {
- tmp = tmp.negate();
- }
- if (tmp == d_true)
- {
- d_regexp_ccached.insert(assertion);
- continue;
- }
- else if (tmp == d_false)
- {
- Node antec = mkRegExpAntec(assertion, mkExplain(rnfexp));
- Node conc = Node::null();
- sendLemma(antec, conc, "REGEXP NF Conflict");
- addedLemma = true;
- break;
- }
- }
-
- if( polarity ) {
- flag = checkPDerivative(x, r, atom, addedLemma, rnfexp);
- } else {
- if(! options::stringExp()) {
- throw LogicException("Strings Incomplete (due to Negative Membership) by default, try --strings-exp option.");
- }
- }
- if(flag) {
- //check if the term is atomic
- Node xr = getRepresentative( x );
- //Trace("strings-regexp") << xr << " is rep of " << x << std::endl;
- //Assert( d_normal_forms.find( xr )!=d_normal_forms.end() );
- Trace("strings-regexp")
- << "Unroll/simplify membership of atomic term " << xr
- << std::endl;
- // if so, do simple unrolling
- std::vector<Node> nvec;
-
- if (nvec.empty())
- {
- d_regexp_opr.simplify(atom, nvec, polarity);
- }
- Node antec = assertion;
- if (d_regexp_ant.find(assertion) != d_regexp_ant.end())
- {
- antec = d_regexp_ant[assertion];
- for (std::vector<Node>::const_iterator itr = nvec.begin();
- itr < nvec.end();
- itr++)
- {
- if (itr->getKind() == kind::STRING_IN_REGEXP)
- {
- if (d_regexp_ant.find(*itr) == d_regexp_ant.end())
- {
- d_regexp_ant[*itr] = antec;
- }
- }
- }
- }
- antec = NodeManager::currentNM()->mkNode(
- kind::AND, antec, mkExplain(rnfexp));
- Node conc = nvec.size() == 1
- ? nvec[0]
- : NodeManager::currentNM()->mkNode(kind::AND, nvec);
- conc = Rewriter::rewrite(conc);
- sendLemma(antec, conc, "REGEXP_Unfold");
- addedLemma = true;
- if (changed)
- {
- cprocessed.push_back(assertion);
- }
- else
- {
- processed.push_back(assertion);
- }
- // d_regexp_ucached[assertion] = true;
- }
- }
- if(d_conflict) {
- break;
- }
- }
- }
- if( addedLemma ) {
- if( !d_conflict ){
- for( unsigned i=0; i<processed.size(); i++ ) {
- Trace("strings-regexp") << "...add " << processed[i] << " to u-cache." << std::endl;
- d_regexp_ucached.insert(processed[i]);
- }
- for( unsigned i=0; i<cprocessed.size(); i++ ) {
- Trace("strings-regexp") << "...add " << cprocessed[i] << " to c-cache." << std::endl;
- d_regexp_ccached.insert(cprocessed[i]);
- }
- }
- }
-}
-
-bool TheoryStrings::checkPDerivative( Node x, Node r, Node atom, bool &addedLemma, std::vector< Node > &nf_exp ) {
-
- Node antnf = mkExplain(nf_exp);
-
- if(areEqual(x, d_emptyString)) {
- Node exp;
- switch(d_regexp_opr.delta(r, exp)) {
- case 0: {
- Node antec = mkRegExpAntec(atom, x.eqNode(d_emptyString));
- antec = NodeManager::currentNM()->mkNode(kind::AND, antec, antnf);
- sendLemma(antec, exp, "RegExp Delta");
- addedLemma = true;
- d_regexp_ccached.insert(atom);
- return false;
- }
- case 1: {
- d_regexp_ccached.insert(atom);
- break;
- }
- case 2: {
- Node antec = mkRegExpAntec(atom, x.eqNode(d_emptyString));
- antec = NodeManager::currentNM()->mkNode(kind::AND, antec, antnf);
- Node conc = Node::null();
- sendLemma(antec, conc, "RegExp Delta CONFLICT");
- addedLemma = true;
- d_regexp_ccached.insert(atom);
- return false;
- }
- default:
- //Impossible
- break;
- }
- } else {
- /*Node xr = getRepresentative( x );
- if(x != xr) {
- Node n = NodeManager::currentNM()->mkNode(kind::STRING_IN_REGEXP, xr, r);
- Node nn = Rewriter::rewrite( n );
- if(nn == d_true) {
- d_regexp_ccached.insert(atom);
- return false;
- } else if(nn == d_false) {
- Node antec = mkRegExpAntec(atom, x.eqNode(xr));
- Node conc = Node::null();
- sendLemma(antec, conc, "RegExp Delta CONFLICT");
- addedLemma = true;
- d_regexp_ccached.insert(atom);
- return false;
- }
- }*/
- Node sREant = mkRegExpAntec(atom, d_true);
- sREant = NodeManager::currentNM()->mkNode(kind::AND, sREant, antnf);
- if(deriveRegExp( x, r, sREant )) {
- addedLemma = true;
- d_regexp_ccached.insert(atom);
- return false;
- }
- }
- return true;
-}
-
-CVC4::String TheoryStrings::getHeadConst( Node x ) {
- if( x.isConst() ) {
- return x.getConst< String >();
- } else if( x.getKind() == kind::STRING_CONCAT ) {
- if( x[0].isConst() ) {
- return x[0].getConst< String >();
- } else {
- return d_emptyString.getConst< String >();
- }
- } else {
- return d_emptyString.getConst< String >();
- }
-}
-
-bool TheoryStrings::deriveRegExp( Node x, Node r, Node ant ) {
- // TODO cstr in vre
- Assert(x != d_emptyString);
- Trace("regexp-derive") << "TheoryStrings::deriveRegExp: x=" << x << ", r= " << r << std::endl;
- //if(x.isConst()) {
- // Node n = NodeManager::currentNM()->mkNode( kind::STRING_IN_REGEXP, x, r );
- // Node r = Rewriter::rewrite( n );
- // if(n != r) {
- // sendLemma(ant, r, "REGEXP REWRITE");
- // return true;
- // }
- //}
- CVC4::String s = getHeadConst( x );
- if( !s.isEmptyString() && d_regexp_opr.checkConstRegExp( r ) ) {
- Node conc = Node::null();
- Node dc = r;
- bool flag = true;
- for(unsigned i=0; i<s.size(); ++i) {
- CVC4::String c = s.substr(i, 1);
- Node dc2;
- int rt = d_regexp_opr.derivativeS(dc, c, dc2);
- dc = dc2;
- if(rt == 0) {
- //TODO
- } else if(rt == 2) {
- // CONFLICT
- flag = false;
- break;
- }
- }
- // send lemma
- if(flag) {
- if(x.isConst()) {
- Assert(false, "Impossible: TheoryStrings::deriveRegExp: const string in const regular expression.");
- return false;
- } else {
- Assert( x.getKind() == kind::STRING_CONCAT );
- std::vector< Node > vec_nodes;
- for(unsigned int i=1; i<x.getNumChildren(); ++i ) {
- vec_nodes.push_back( x[i] );
- }
- Node left = mkConcat( vec_nodes );
- left = Rewriter::rewrite( left );
- conc = NodeManager::currentNM()->mkNode( kind::STRING_IN_REGEXP, left, dc );
-
- /*std::vector< Node > sdc;
- d_regexp_opr.simplify(conc, sdc, true);
- if(sdc.size() == 1) {
- conc = sdc[0];
- } else {
- conc = Rewriter::rewrite(NodeManager::currentNM()->mkNode(kind::AND, conc));
- }*/
- }
- }
- sendLemma(ant, conc, "RegExp-Derive");
- return true;
- } else {
- return false;
- }
-}
-
-void TheoryStrings::addMembership(Node assertion) {
- bool polarity = assertion.getKind() != kind::NOT;
- TNode atom = polarity ? assertion : assertion[0];
- Node x = atom[0];
- Node r = atom[1];
- if(polarity) {
- int index = 0;
- NodeIntMap::const_iterator it = d_pos_memberships.find( x );
- if( it!=d_nf_pairs.end() ){
- index = (*it).second;
- for( int k=0; k<index; k++ ){
- if( k<(int)d_pos_memberships_data[x].size() ){
- if( d_pos_memberships_data[x][k]==r ){
- return;
- }
- }else{
- break;
- }
- }
- }
- d_pos_memberships[x] = index + 1;
- if( index<(int)d_pos_memberships_data[x].size() ){
- d_pos_memberships_data[x][index] = r;
- }else{
- d_pos_memberships_data[x].push_back( r );
- }
- } else if(!options::stringIgnNegMembership()) {
- /*if(options::stringEIT() && d_regexp_opr.checkConstRegExp(r)) {
- int rt;
- Node r2 = d_regexp_opr.complement(r, rt);
- Node a = NodeManager::currentNM()->mkNode(kind::STRING_IN_REGEXP, x, r2);
- }*/
- int index = 0;
- NodeIntMap::const_iterator it = d_neg_memberships.find( x );
- if( it!=d_nf_pairs.end() ){
- index = (*it).second;
- for( int k=0; k<index; k++ ){
- if( k<(int)d_neg_memberships_data[x].size() ){
- if( d_neg_memberships_data[x][k]==r ){
- return;
- }
- }else{
- break;
- }
- }
- }
- d_neg_memberships[x] = index + 1;
- if( index<(int)d_neg_memberships_data[x].size() ){
- d_neg_memberships_data[x][index] = r;
- }else{
- d_neg_memberships_data[x].push_back( r );
- }
- }
- // old
- if(polarity || !options::stringIgnNegMembership()) {
- d_regexp_memberships.push_back( assertion );
- }
-}
-
-Node TheoryStrings::getNormalString( Node x, std::vector< Node >& nf_exp ){
- if( !x.isConst() ){
- Node xr = getRepresentative( x );
- if( d_normal_forms.find( xr ) != d_normal_forms.end() ){
- Node ret = mkConcat( d_normal_forms[xr] );
- nf_exp.insert( nf_exp.end(), d_normal_forms_exp[xr].begin(), d_normal_forms_exp[xr].end() );
- addToExplanation( x, d_normal_forms_base[xr], nf_exp );
- Trace("strings-debug") << "Term: " << x << " has a normal form " << ret << std::endl;
- return ret;
- } else {
- if(x.getKind() == kind::STRING_CONCAT) {
- std::vector< Node > vec_nodes;
- for(unsigned i=0; i<x.getNumChildren(); i++) {
- Node nc = getNormalString( x[i], nf_exp );
- vec_nodes.push_back( nc );
- }
- return mkConcat( vec_nodes );
- }
- }
- }
- return x;
-}
-
-Node TheoryStrings::getNormalSymRegExp(Node r, std::vector<Node> &nf_exp) {
- Node ret = r;
- switch( r.getKind() ) {
- case kind::REGEXP_EMPTY:
- case kind::REGEXP_SIGMA:
- break;
- case kind::STRING_TO_REGEXP: {
- if(!r[0].isConst()) {
- Node tmp = getNormalString( r[0], nf_exp );
- if(tmp != r[0]) {
- ret = NodeManager::currentNM()->mkNode(kind::STRING_TO_REGEXP, tmp);
- }
- }
- break;
- }
- case kind::REGEXP_CONCAT:
- case kind::REGEXP_UNION:
- case kind::REGEXP_INTER:
- case kind::REGEXP_STAR:
- {
- std::vector< Node > vec_nodes;
- for (const Node& cr : r)
- {
- vec_nodes.push_back(getNormalSymRegExp(cr, nf_exp));
- }
- ret = Rewriter::rewrite(
- NodeManager::currentNM()->mkNode(r.getKind(), vec_nodes));
- break;
- }
- //case kind::REGEXP_PLUS:
- //case kind::REGEXP_OPT:
- //case kind::REGEXP_RANGE:
- default: {
- Trace("strings-error") << "Unsupported term: " << r << " in normalization SymRegExp." << std::endl;
- Assert( false );
- //return Node::null();
- }
- }
- return ret;
}
/** run the given inference step */