src/theory/rep_set.cpp

   1 /*********************                                                        */
   2 /*! \file rep_set.cpp
   3  ** \verbatim
   4  ** Top contributors (to current version):
   5  **   Andrew Reynolds, Morgan Deters, Tim King
   6  ** This file is part of the CVC4 project.
   7  ** Copyright (c) 2009-2016 by the authors listed in the file AUTHORS
   8  ** in the top-level source directory) and their institutional affiliations.
   9  ** All rights reserved.  See the file COPYING in the top-level source
  10  ** directory for licensing information.\endverbatim
  11  **
  12  ** \brief Implementation of representative set
  13  **/
  14
  15 #include "theory/rep_set.h"
  16 #include "theory/type_enumerator.h"
  17 #include "theory/quantifiers/bounded_integers.h"
  18 #include "theory/quantifiers/term_database.h"
  19 #include "theory/quantifiers/first_order_model.h"
  20
  21 using namespace std;
  22 using namespace CVC4;
  23 using namespace CVC4::kind;
  24 using namespace CVC4::context;
  25 using namespace CVC4::theory;
  26
  27 void RepSet::clear(){
  28   d_type_reps.clear();
  29   d_type_complete.clear();
  30   d_tmap.clear();
  31   d_values_to_terms.clear();
  32 }
  33
  34 bool RepSet::hasRep( TypeNode tn, Node n ) {
  35   std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.find( tn );
  36   if( it==d_type_reps.end() ){
  37     return false;
  38   }else{
  39     return std::find( it->second.begin(), it->second.end(), n )!=it->second.end();
  40   }
  41 }
  42
  43 int RepSet::getNumRepresentatives( TypeNode tn ) const{
  44   std::map< TypeNode, std::vector< Node > >::const_iterator it = d_type_reps.find( tn );
  45   if( it!=d_type_reps.end() ){
  46     return (int)it->second.size();
  47   }else{
  48     return 0;
  49   }
  50 }
  51
  52 bool containsStoreAll( Node n, std::vector< Node >& cache ){
  53   if( std::find( cache.begin(), cache.end(), n )==cache.end() ){
  54     cache.push_back( n );
  55     if( n.getKind()==STORE_ALL ){
  56       return true;
  57     }else{
  58       for( unsigned i=0; i<n.getNumChildren(); i++ ){
  59         if( containsStoreAll( n[i], cache ) ){
  60           return true;
  61         }
  62       }
  63     }
  64   }
  65   return false;
  66 }
  67
  68 void RepSet::add( TypeNode tn, Node n ){
  69   //for now, do not add array constants FIXME
  70   if( tn.isArray() ){
  71     std::vector< Node > cache;
  72     if( containsStoreAll( n, cache ) ){
  73       return;
  74     }
  75   }
  76   Trace("rsi-debug") << "Add rep #" << d_type_reps[tn].size() << " for " << tn << " : " << n << std::endl;
  77   Assert( n.getType().isSubtypeOf( tn ) );
  78   d_tmap[ n ] = (int)d_type_reps[tn].size();
  79   d_type_reps[tn].push_back( n );
  80 }
  81
  82 int RepSet::getIndexFor( Node n ) const {
  83   std::map< Node, int >::const_iterator it = d_tmap.find( n );
  84   if( it!=d_tmap.end() ){
  85     return it->second;
  86   }else{
  87     return -1;
  88   }
  89 }
  90
  91 bool RepSet::complete( TypeNode t ){
  92   std::map< TypeNode, bool >::iterator it = d_type_complete.find( t );
  93   if( it==d_type_complete.end() ){
  94     //remove all previous
  95     for( unsigned i=0; i<d_type_reps[t].size(); i++ ){
  96       d_tmap.erase( d_type_reps[t][i] );
  97     }
  98     d_type_reps[t].clear();
  99     //now complete the type
 100     d_type_complete[t] = true;
 101     TypeEnumerator te(t);
 102     while( !te.isFinished() ){
 103       Node n = *te;
 104       if( std::find( d_type_reps[t].begin(), d_type_reps[t].end(), n )==d_type_reps[t].end() ){
 105         add( t, n );
 106       }
 107       ++te;
 108     }
 109     for( size_t i=0; i<d_type_reps[t].size(); i++ ){
 110       Trace("reps-complete") << d_type_reps[t][i] << " ";
 111     }
 112     Trace("reps-complete") << std::endl;
 113     return true;
 114   }else{
 115     return it->second;
 116   }
 117 }
 118
 119 void RepSet::toStream(std::ostream& out){
 120   for( std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.begin(); it != d_type_reps.end(); ++it ){
 121     if( !it->first.isFunction() && !it->first.isPredicate() ){
 122       out << "(" << it->first << " " << it->second.size();
 123       out << " (";
 124       for( unsigned i=0; i<it->second.size(); i++ ){
 125         if( i>0 ){ out << " "; }
 126         out << it->second[i];
 127       }
 128       out << ")";
 129       out << ")" << std::endl;
 130     }
 131   }
 132 }
 133
 134
 135 RepSetIterator::RepSetIterator( QuantifiersEngine * qe, RepSet* rs ) : d_qe(qe), d_rep_set( rs ){
 136   d_incomplete = false;
 137 }
 138
 139 int RepSetIterator::domainSize( int i ) {
 140   Assert(i>=0);
 141   int v = d_var_order[i];
 142   if( d_enum_type[v]==ENUM_DOMAIN_ELEMENTS ){
 143     return d_domain[v].size();
 144   }else{
 145     return d_domain[v][0];
 146   }
 147 }
 148
 149 bool RepSetIterator::setQuantifier( Node f ){
 150   Trace("rsi") << "Make rsi for " << f << std::endl;
 151   Assert( d_types.empty() );
 152   //store indicies
 153   for( size_t i=0; i<f[0].getNumChildren(); i++ ){
 154     d_types.push_back( f[0][i].getType() );
 155   }
 156   d_owner = f;
 157   return initialize();
 158 }
 159
 160 bool RepSetIterator::setFunctionDomain( Node op ){
 161   Trace("rsi") << "Make rsi for " << op << std::endl;
 162   Assert( d_types.empty() );
 163   TypeNode tn = op.getType();
 164   for( size_t i=0; i<tn.getNumChildren()-1; i++ ){
 165     d_types.push_back( tn[i] );
 166   }
 167   d_owner = op;
 168   return initialize();
 169 }
 170
 171 bool RepSetIterator::initialize(){
 172   Trace("rsi") << "Initialize rep set iterator..." << std::endl;
 173   for( unsigned v=0; v<d_types.size(); v++ ){
 174     d_index.push_back( 0 );
 175     //store default index order
 176     d_index_order.push_back( v );
 177     d_var_order[v] = v;
 178     //store default domain
 179     d_domain.push_back( RepDomain() );
 180     TypeNode tn = d_types[v];
 181     Trace("rsi") << "Var #" << v << " is type " << tn << "..." << std::endl;
 182     if( tn.isSort() ){
 183       //must ensure uninterpreted type is non-empty.
 184       if( !d_rep_set->hasType( tn ) ){
 185         //FIXME:
 186         // terms in rep_set are now constants which mapped to terms through TheoryModel
 187         // thus, should introduce a constant and a term.  for now, just a term.
 188
 189         //Node c = d_qe->getTermDatabase()->getEnumerateTerm( tn, 0 );
 190         Node var = d_qe->getModel()->getSomeDomainElement( tn );
 191         Trace("mkVar") << "RepSetIterator:: Make variable " << var << " : " << tn << std::endl;
 192         d_rep_set->add( tn, var );
 193       }
 194     }else{
 195       bool inc = true;
 196       //check if it is bound by bounded integer module
 197       if( d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers() ){
 198         unsigned bvt = d_qe->getBoundedIntegers()->getBoundVarType( d_owner, d_owner[0][v] );
 199         if( bvt==quantifiers::BoundedIntegers::BOUND_INT_RANGE ){
 200           Trace("rsi") << "  variable is bounded integer." << std::endl;
 201           d_enum_type.push_back( ENUM_INT_RANGE );
 202           inc = false;
 203         }else if( bvt==quantifiers::BoundedIntegers::BOUND_SET_MEMBER ){
 204           Trace("rsi") << "  variable is bounded by set membership." << std::endl;
 205           d_enum_type.push_back( ENUM_SET_MEMBERS );
 206           inc = false;
 207         }
 208       }
 209       if( inc ){
 210         //check if it is otherwise bound
 211         if( d_bounds[0].find( v )!=d_bounds[0].end() && d_bounds[1].find( v )!=d_bounds[1].end() ){
 212           Trace("rsi") << "  variable is bounded." << std::endl;
 213           d_enum_type.push_back( ENUM_INT_RANGE );
 214         }else if( d_qe->getTermDatabase()->mayComplete( tn ) ){
 215           Trace("rsi") << "  do complete, since cardinality is small (" << tn.getCardinality() << ")..." << std::endl;
 216           d_rep_set->complete( tn );
 217           //must have succeeded
 218           Assert( d_rep_set->hasType( tn ) );
 219         }else{
 220           Trace("rsi") << "  variable cannot be bounded." << std::endl;
 221           Trace("fmf-incomplete") << "Incomplete because of quantification of type " << tn << std::endl;
 222           d_incomplete = true;
 223         }
 224       }
 225     }
 226     //if we have yet to determine the type of enumeration
 227     if( d_enum_type.size()<=v ){
 228       d_enum_type.push_back( ENUM_DOMAIN_ELEMENTS );
 229       if( d_rep_set->hasType( tn ) ){
 230         for( unsigned j=0; j<d_rep_set->d_type_reps[tn].size(); j++ ){
 231           d_domain[v].push_back( j );
 232         }
 233       }else{
 234         Assert( d_incomplete );
 235         return false;
 236       }
 237     }
 238   }
 239   //must set a variable index order based on bounded integers
 240   if( d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers() ){
 241     Trace("bound-int-rsi") << "Calculating variable order..." << std::endl;
 242     std::vector< int > varOrder;
 243     for( unsigned i=0; i<d_qe->getBoundedIntegers()->getNumBoundVars( d_owner ); i++ ){
 244       Node v = d_qe->getBoundedIntegers()->getBoundVar( d_owner, i );
 245       Trace("bound-int-rsi") << "  bound var #" << i << " is " << v << std::endl;
 246       varOrder.push_back( d_qe->getTermDatabase()->getVariableNum( d_owner, v ) );
 247     }
 248     for( unsigned i=0; i<d_owner[0].getNumChildren(); i++) {
 249       if( !d_qe->getBoundedIntegers()->isBoundVar(d_owner, d_owner[0][i])) {
 250         varOrder.push_back(i);
 251       }
 252     }
 253     Trace("bound-int-rsi") << "Variable order : ";
 254     for( unsigned i=0; i<varOrder.size(); i++) {
 255       Trace("bound-int-rsi") << varOrder[i] << " ";
 256     }
 257     Trace("bound-int-rsi") << std::endl;
 258     std::vector< int > indexOrder;
 259     indexOrder.resize(varOrder.size());
 260     for( unsigned i=0; i<varOrder.size(); i++){
 261       indexOrder[varOrder[i]] = i;
 262     }
 263     Trace("bound-int-rsi") << "Will use index order : ";
 264     for( unsigned i=0; i<indexOrder.size(); i++) {
 265       Trace("bound-int-rsi") << indexOrder[i] << " ";
 266     }
 267     Trace("bound-int-rsi") << std::endl;
 268     setIndexOrder( indexOrder );
 269   }
 270   //now reset the indices
 271   do_reset_increment( -1, true );
 272   return true;
 273 }
 274
 275 void RepSetIterator::setIndexOrder( std::vector< int >& indexOrder ){
 276   d_index_order.clear();
 277   d_index_order.insert( d_index_order.begin(), indexOrder.begin(), indexOrder.end() );
 278   //make the d_var_order mapping
 279   for( unsigned i=0; i<d_index_order.size(); i++ ){
 280     d_var_order[d_index_order[i]] = i;
 281   }
 282 }
 283
 284 int RepSetIterator::resetIndex( int i, bool initial ) {
 285   d_index[i] = 0;
 286   int v = d_var_order[i];
 287   Trace("bound-int-rsi") << "Reset " << i << ", var order = " << v << ", initial = " << initial << std::endl;
 288   //determine the current range
 289   if( initial || ( d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers() &&
 290                    d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][v] ) &&
 291                    !d_qe->getBoundedIntegers()->isGroundRange( d_owner, d_owner[0][v] ) ) ){
 292     Trace("bound-int-rsi") << "Getting range of " << d_owner[0][v] << std::endl;
 293     if( d_enum_type[v]==ENUM_INT_RANGE ){
 294       Node actual_l;
 295       Node l, u;
 296       if( d_qe->getBoundedIntegers() ){
 297         unsigned bvt = d_qe->getBoundedIntegers()->getBoundVarType( d_owner, d_owner[0][v] );
 298         if( bvt==quantifiers::BoundedIntegers::BOUND_INT_RANGE ){
 299           d_qe->getBoundedIntegers()->getBoundValues( d_owner, d_owner[0][v], this, l, u );
 300         }
 301       }
 302       for( unsigned b=0; b<2; b++ ){
 303         if( d_bounds[b].find(v)!=d_bounds[b].end() ){
 304           Trace("bound-int-rsi") << "May further limit bound(" << b << ") based on " << d_bounds[b][v] << std::endl;
 305           if( b==0 && (l.isNull() || d_bounds[b][v].getConst<Rational>() > l.getConst<Rational>()) ){
 306             if( !l.isNull() ){
 307               //bound was limited externally, record that the value lower bound is not equal to the term lower bound
 308               actual_l = NodeManager::currentNM()->mkNode( MINUS, d_bounds[b][v], l );
 309             }
 310             l = d_bounds[b][v];
 311           }else if( b==1 && (u.isNull() || d_bounds[b][v].getConst<Rational>() <= u.getConst<Rational>()) ){
 312             u = NodeManager::currentNM()->mkNode( MINUS, d_bounds[b][v],
 313                                                   NodeManager::currentNM()->mkConst( Rational(1) ) );
 314             u = Rewriter::rewrite( u );
 315           }
 316         }
 317       }
 318
 319       if( l.isNull() || u.isNull() ){
 320         //failed, abort the iterator
 321         return -1;
 322       }else{
 323         Trace("bound-int-rsi") << "Can limit bounds of " << d_owner[0][v] << " to " << l << "..." << u << std::endl;
 324         Node range = Rewriter::rewrite( NodeManager::currentNM()->mkNode( MINUS, u, l ) );
 325         Node ra = Rewriter::rewrite( NodeManager::currentNM()->mkNode( LEQ, range, NodeManager::currentNM()->mkConst( Rational( 9999 ) ) ) );
 326         d_domain[v].clear();
 327         Node tl = l;
 328         Node tu = u;
 329         if( d_qe->getBoundedIntegers() && d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][v] ) ){
 330           d_qe->getBoundedIntegers()->getBounds( d_owner, d_owner[0][v], this, tl, tu );
 331         }
 332         d_lower_bounds[v] = tl;
 333         if( !actual_l.isNull() ){
 334           //if bound was limited externally, must consider the offset
 335           d_lower_bounds[v] = Rewriter::rewrite( NodeManager::currentNM()->mkNode( PLUS, tl, actual_l ) );
 336         }
 337         if( ra==d_qe->getTermDatabase()->d_true ){
 338           long rr = range.getConst<Rational>().getNumerator().getLong()+1;
 339           Trace("bound-int-rsi")  << "Actual bound range is " << rr << std::endl;
 340           d_domain[v].push_back( (int)rr );
 341           if( rr<=0 ){
 342             return 0;
 343           }
 344         }else{
 345           Trace("fmf-incomplete") << "Incomplete because of integer quantification, bounds are too big for " << d_owner[0][v] << "." << std::endl;
 346           return -1;
 347         }
 348       }
 349     }else if( d_enum_type[v]==ENUM_SET_MEMBERS ){
 350       Assert( d_qe->getBoundedIntegers()->getBoundVarType( d_owner, d_owner[0][v] )==quantifiers::BoundedIntegers::BOUND_SET_MEMBER );
 351       Node srv = d_qe->getBoundedIntegers()->getSetRangeValue( d_owner, d_owner[0][v], this );
 352       if( srv.isNull() ){
 353         return -1;
 354       }
 355       Trace("bound-int-rsi") << "Bounded by set membership : " << srv << std::endl;
 356       d_domain[v].clear();
 357       d_setm_bounds[v].clear();
 358       if( srv.getKind()!=EMPTYSET ){
 359         while( srv.getKind()==UNION ){
 360           Assert( srv[1].getKind()==kind::SINGLETON );
 361           d_setm_bounds[v].push_back( srv[1][0] );
 362           srv = srv[0];
 363         }
 364         Assert( srv.getKind()==kind::SINGLETON );
 365         d_setm_bounds[v].push_back( srv[0] );
 366         d_domain[v].push_back( d_setm_bounds[v].size() );
 367       }else{
 368         d_domain[v].push_back( 0 );
 369         return 0;
 370       }
 371     }
 372   }
 373   return 1;
 374 }
 375
 376 int RepSetIterator::increment2( int i ){
 377   Assert( !isFinished() );
 378 #ifdef DISABLE_EVAL_SKIP_MULTIPLE
 379   i = (int)d_index.size()-1;
 380 #endif
 381   //increment d_index
 382   if( i>=0){
 383     Trace("rsi-debug") << "domain size of " << i << " is " << domainSize(i) << std::endl;
 384   }
 385   while( i>=0 && d_index[i]>=(int)(domainSize(i)-1) ){
 386     i--;
 387     if( i>=0){
 388       Trace("rsi-debug") << "domain size of " << i << " is " << domainSize(i) << std::endl;
 389     }
 390   }
 391   if( i==-1 ){
 392     d_index.clear();
 393     return -1;
 394   }else{
 395     Trace("rsi-debug") << "increment " << i << std::endl;
 396     d_index[i]++;
 397     return do_reset_increment( i );
 398   }
 399 }
 400
 401 int RepSetIterator::do_reset_increment( int i, bool initial ) {
 402   bool emptyDomain = false;
 403   for( unsigned ii=(i+1); ii<d_index.size(); ii++ ){
 404     int ri_res = resetIndex( ii, initial );
 405     if( ri_res==-1 ){
 406       //failed
 407       d_index.clear();
 408       d_incomplete = true;
 409       break;
 410     }else if( ri_res==0 ){
 411       emptyDomain = true;
 412     }
 413     //force next iteration if currently an empty domain
 414     if( emptyDomain ){
 415       d_index[ii] = domainSize(ii)-1;
 416     }
 417   }
 418   if( emptyDomain ){
 419     Trace("rsi-debug") << "This is an empty domain, increment." << std::endl;
 420     return increment();
 421   }else{
 422     return i;
 423   }
 424 }
 425
 426 int RepSetIterator::increment(){
 427   if( !isFinished() ){
 428     return increment2( (int)d_index.size()-1 );
 429   }else{
 430     return -1;
 431   }
 432 }
 433
 434 bool RepSetIterator::isFinished(){
 435   return d_index.empty();
 436 }
 437
 438 Node RepSetIterator::getCurrentTerm( int v ){
 439   Trace("rsi-debug") << "rsi : get term " << v << ", index order = " << d_index_order[v] << std::endl;
 440   int ii = d_index_order[v];
 441   int curr = d_index[ii];
 442   if( d_enum_type[v]==ENUM_DOMAIN_ELEMENTS ){
 443     TypeNode tn = d_types[v];
 444     Assert( d_rep_set->d_type_reps.find( tn )!=d_rep_set->d_type_reps.end() );
 445     Assert( 0<=d_domain[v][curr] && d_domain[v][curr]<(int)d_rep_set->d_type_reps[tn].size() );
 446     return d_rep_set->d_type_reps[tn][d_domain[v][curr]];
 447   }else if( d_enum_type[v]==ENUM_SET_MEMBERS ){
 448     Assert( 0<=curr && curr<(int)d_setm_bounds[v].size() );
 449     return d_setm_bounds[v][curr];
 450   }else{
 451     Trace("rsi-debug") << "Get, with offset : " << v << " " << d_lower_bounds[v] << " " << curr << std::endl;
 452     Assert( !d_lower_bounds[v].isNull() );
 453     Node t = NodeManager::currentNM()->mkNode(PLUS, d_lower_bounds[v], NodeManager::currentNM()->mkConst( Rational(curr) ) );
 454     t = Rewriter::rewrite( t );
 455     return t;
 456   }
 457 }
 458
 459 void RepSetIterator::debugPrint( const char* c ){
 460   for( unsigned v=0; v<d_index.size(); v++ ){
 461     Debug( c ) << v << " : " << getCurrentTerm( v ) << std::endl;
 462   }
 463 }
 464
 465 void RepSetIterator::debugPrintSmall( const char* c ){
 466   Debug( c ) << "RI: ";
 467   for( unsigned v=0; v<d_index.size(); v++ ){
 468     Debug( c ) << v << ": " << getCurrentTerm( v ) << " ";
 469   }
 470   Debug( c ) << std::endl;
 471 }
 472