src/theory/rep_set.cpp

   1 /*********************                                                        */
   2 /*! \file rep_set.cpp
   3  ** \verbatim
   4  ** Original author: Andrew Reynolds
   5  ** Major contributors: Morgan Deters
   6  ** Minor contributors (to current version): Kshitij Bansal
   7  ** This file is part of the CVC4 project.
   8  ** Copyright (c) 2009-2014  New York University and The University of Iowa
   9  ** See the file COPYING in the top-level source directory for licensing
  10  ** 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
  19 using namespace std;
  20 using namespace CVC4;
  21 using namespace CVC4::kind;
  22 using namespace CVC4::context;
  23 using namespace CVC4::theory;
  24
  25 void RepSet::clear(){
  26   d_type_reps.clear();
  27   d_type_complete.clear();
  28   d_tmap.clear();
  29 }
  30
  31 bool RepSet::hasRep( TypeNode tn, Node n ) {
  32   std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.find( tn );
  33   if( it==d_type_reps.end() ){
  34     return false;
  35   }else{
  36     return std::find( it->second.begin(), it->second.end(), n )!=it->second.end();
  37   }
  38 }
  39
  40 int RepSet::getNumRepresentatives( TypeNode tn ) const{
  41   std::map< TypeNode, std::vector< Node > >::const_iterator it = d_type_reps.find( tn );
  42   if( it!=d_type_reps.end() ){
  43     return (int)it->second.size();
  44   }else{
  45     return 0;
  46   }
  47 }
  48
  49 void RepSet::add( TypeNode tn, Node n ){
  50   Trace("rsi-debug") << "Add rep #" << d_type_reps[tn].size() << " for " << tn << " : " << n << std::endl;
  51   Assert( n.getType().isSubtypeOf( tn ) );
  52   d_tmap[ n ] = (int)d_type_reps[tn].size();
  53   d_type_reps[tn].push_back( n );
  54 }
  55
  56 int RepSet::getIndexFor( Node n ) const {
  57   std::map< Node, int >::const_iterator it = d_tmap.find( n );
  58   if( it!=d_tmap.end() ){
  59     return it->second;
  60   }else{
  61     return -1;
  62   }
  63 }
  64
  65 void RepSet::complete( TypeNode t ){
  66   if( d_type_complete.find( t )==d_type_complete.end() ){
  67     d_type_complete[t] = true;
  68     TypeEnumerator te(t);
  69     while( !te.isFinished() ){
  70       Node n = *te;
  71       if( std::find( d_type_reps[t].begin(), d_type_reps[t].end(), n )==d_type_reps[t].end() ){
  72         add( t, n );
  73       }
  74       ++te;
  75     }
  76     for( size_t i=0; i<d_type_reps[t].size(); i++ ){
  77       Trace("reps-complete") << d_type_reps[t][i] << " ";
  78     }
  79     Trace("reps-complete") << std::endl;
  80   }
  81 }
  82
  83 void RepSet::toStream(std::ostream& out){
  84 #if 0
  85   for( std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.begin(); it != d_type_reps.end(); ++it ){
  86     out << it->first << " : " << std::endl;
  87     for( int i=0; i<(int)it->second.size(); i++ ){
  88       out << "   " << i << ": " << it->second[i] << std::endl;
  89     }
  90   }
  91 #else
  92   for( std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.begin(); it != d_type_reps.end(); ++it ){
  93     if( !it->first.isFunction() && !it->first.isPredicate() ){
  94       out << "(" << it->first << " " << it->second.size();
  95       out << " (";
  96       for( int i=0; i<(int)it->second.size(); i++ ){
  97         if( i>0 ){ out << " "; }
  98         out << it->second[i];
  99       }
 100       out << ")";
 101       out << ")" << std::endl;
 102     }
 103   }
 104 #endif
 105 }
 106
 107
 108 RepSetIterator::RepSetIterator( QuantifiersEngine * qe, RepSet* rs ) : d_qe(qe), d_rep_set( rs ){
 109   d_incomplete = false;
 110 }
 111
 112 int RepSetIterator::domainSize( int i ) {
 113   Assert(i>=0);
 114   if( d_enum_type[i]==ENUM_DOMAIN_ELEMENTS ){
 115     return d_domain[i].size();
 116   }else{
 117     return d_domain[i][0];
 118   }
 119 }
 120
 121 bool RepSetIterator::setQuantifier( Node f ){
 122   Trace("rsi") << "Make rsi for " << f << std::endl;
 123   Assert( d_types.empty() );
 124   //store indicies
 125   for( size_t i=0; i<f[0].getNumChildren(); i++ ){
 126     d_types.push_back( f[0][i].getType() );
 127   }
 128   d_owner = f;
 129   return initialize();
 130 }
 131
 132 bool RepSetIterator::setFunctionDomain( Node op ){
 133   Trace("rsi") << "Make rsi for " << op << std::endl;
 134   Assert( d_types.empty() );
 135   TypeNode tn = op.getType();
 136   for( size_t i=0; i<tn.getNumChildren()-1; i++ ){
 137     d_types.push_back( tn[i] );
 138   }
 139   d_owner = op;
 140   return initialize();
 141 }
 142
 143 bool RepSetIterator::initialize(){
 144   for( size_t i=0; i<d_types.size(); i++ ){
 145     d_index.push_back( 0 );
 146     //store default index order
 147     d_index_order.push_back( i );
 148     d_var_order[i] = i;
 149     //store default domain
 150     d_domain.push_back( RepDomain() );
 151     TypeNode tn = d_types[i];
 152     if( tn.isSort() ){
 153       if( !d_rep_set->hasType( tn ) ){
 154         Node var = NodeManager::currentNM()->mkSkolem( "repSet", tn, "is a variable created by the RepSetIterator" );
 155         Trace("mkVar") << "RepSetIterator:: Make variable " << var << " : " << tn << std::endl;
 156         d_rep_set->add( tn, var );
 157       }
 158     }else if( tn.isInteger() ){
 159       bool inc = false;
 160       //check if it is bound
 161       if( d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers() ){
 162         if( d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][i] ) ){
 163           Trace("bound-int-rsi") << "Rep set iterator: variable #" << i << " is bounded integer." << std::endl;
 164           d_enum_type.push_back( ENUM_RANGE );
 165         }else{
 166           inc = true;
 167         }
 168       }else{
 169         inc = true;
 170       }
 171       if( inc ){
 172         //check if it is otherwise bound
 173         if( d_bounds[0].find(i)!=d_bounds[0].end() && d_bounds[1].find(i)!=d_bounds[1].end() ){
 174           Trace("bound-int-rsi") << "Rep set iterator: variable #" << i << " is bounded." << std::endl;
 175           d_enum_type.push_back( ENUM_RANGE );
 176         }else{
 177           Trace("fmf-incomplete") << "Incomplete because of integer quantification of " << d_owner[0][i] << "." << std::endl;
 178           d_incomplete = true;
 179         }
 180       }
 181     //enumerate if the sort is reasonably small, the upper bound of 1000 is chosen arbitrarily for now
 182     }else if( tn.getCardinality().isFinite() && !tn.getCardinality().isLargeFinite() &&
 183               tn.getCardinality().getFiniteCardinality().toUnsignedInt()<=1000 ){
 184       d_rep_set->complete( tn );
 185     }else{
 186       Trace("fmf-incomplete") << "Incomplete because of quantification of type " << tn << std::endl;
 187       d_incomplete = true;
 188     }
 189     if( d_enum_type.size()<=i ){
 190       d_enum_type.push_back( ENUM_DOMAIN_ELEMENTS );
 191       if( d_rep_set->hasType( tn ) ){
 192         for( size_t j=0; j<d_rep_set->d_type_reps[tn].size(); j++ ){
 193           d_domain[i].push_back( j );
 194         }
 195       }else{
 196         return false;
 197       }
 198     }
 199   }
 200   //must set a variable index order based on bounded integers
 201   if (d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers()) {
 202     Trace("bound-int-rsi") << "Calculating variable order..." << std::endl;
 203     std::vector< int > varOrder;
 204     for( unsigned i=0; i<d_qe->getBoundedIntegers()->getNumBoundVars(d_owner); i++ ){
 205       varOrder.push_back(d_qe->getBoundedIntegers()->getBoundVarNum(d_owner,i));
 206     }
 207     for( unsigned i=0; i<d_owner[0].getNumChildren(); i++) {
 208       if( !d_qe->getBoundedIntegers()->isBoundVar(d_owner, d_owner[0][i])) {
 209         varOrder.push_back(i);
 210       }
 211     }
 212     Trace("bound-int-rsi") << "Variable order : ";
 213     for( unsigned i=0; i<varOrder.size(); i++) {
 214       Trace("bound-int-rsi") << varOrder[i] << " ";
 215     }
 216     Trace("bound-int-rsi") << std::endl;
 217     std::vector< int > indexOrder;
 218     indexOrder.resize(varOrder.size());
 219     for( unsigned i=0; i<varOrder.size(); i++){
 220       indexOrder[varOrder[i]] = i;
 221     }
 222     Trace("bound-int-rsi") << "Will use index order : ";
 223     for( unsigned i=0; i<indexOrder.size(); i++) {
 224       Trace("bound-int-rsi") << indexOrder[i] << " ";
 225     }
 226     Trace("bound-int-rsi") << std::endl;
 227     setIndexOrder(indexOrder);
 228   }
 229   //now reset the indices
 230   for (unsigned i=0; i<d_index.size(); i++) {
 231     if (!resetIndex(i, true)){
 232       break;
 233     }
 234   }
 235   return true;
 236 }
 237
 238 void RepSetIterator::setIndexOrder( std::vector< int >& indexOrder ){
 239   d_index_order.clear();
 240   d_index_order.insert( d_index_order.begin(), indexOrder.begin(), indexOrder.end() );
 241   //make the d_var_order mapping
 242   for( int i=0; i<(int)d_index_order.size(); i++ ){
 243     d_var_order[d_index_order[i]] = i;
 244   }
 245 }
 246 /*
 247 void RepSetIterator::setDomain( std::vector< RepDomain >& domain ){
 248   d_domain.clear();
 249   d_domain.insert( d_domain.begin(), domain.begin(), domain.end() );
 250   //we are done if a domain is empty
 251   for( int i=0; i<(int)d_domain.size(); i++ ){
 252     if( d_domain[i].empty() ){
 253       d_index.clear();
 254     }
 255   }
 256 }
 257 */
 258 bool RepSetIterator::resetIndex( int i, bool initial ) {
 259   d_index[i] = 0;
 260   int ii = d_index_order[i];
 261   Trace("bound-int-rsi") << "Reset " << i << " " << ii << " " << initial << std::endl;
 262   //determine the current range
 263   if( d_enum_type[ii]==ENUM_RANGE ){
 264     if( initial || ( d_qe->getBoundedIntegers() && !d_qe->getBoundedIntegers()->isGroundRange( d_owner, d_owner[0][ii] ) ) ){
 265       Trace("bound-int-rsi") << "Getting range of " << d_owner[0][ii] << std::endl;
 266       Node actual_l;
 267       Node l, u;
 268       if( d_qe->getBoundedIntegers() && d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][ii] ) ){
 269         d_qe->getBoundedIntegers()->getBoundValues( d_owner, d_owner[0][ii], this, l, u );
 270       }
 271       for( unsigned b=0; b<2; b++ ){
 272         if( d_bounds[b].find(ii)!=d_bounds[b].end() ){
 273           Trace("bound-int-rsi") << "May further limit bound(" << b << ") based on " << d_bounds[b][ii] << std::endl;
 274           if( b==0 && (l.isNull() || d_bounds[b][ii].getConst<Rational>() > l.getConst<Rational>()) ){
 275             if( !l.isNull() ){
 276               //bound was limited externally, record that the value lower bound is not equal to the term lower bound
 277               actual_l = NodeManager::currentNM()->mkNode( MINUS, d_bounds[b][ii], l );
 278             }
 279             l = d_bounds[b][ii];
 280           }else if( b==1 && (u.isNull() || d_bounds[b][ii].getConst<Rational>() <= u.getConst<Rational>()) ){
 281             u = NodeManager::currentNM()->mkNode( MINUS, d_bounds[b][ii],
 282                                                   NodeManager::currentNM()->mkConst( Rational(1) ) );
 283             u = Rewriter::rewrite( u );
 284           }
 285         }
 286       }
 287
 288       if( l.isNull() || u.isNull() ){
 289         //failed, abort the iterator
 290         d_index.clear();
 291         return false;
 292       }else{
 293         Trace("bound-int-rsi") << "Can limit bounds of " << d_owner[0][ii] << " to " << l << "..." << u << std::endl;
 294         Node range = Rewriter::rewrite( NodeManager::currentNM()->mkNode( MINUS, u, l ) );
 295         Node ra = Rewriter::rewrite( NodeManager::currentNM()->mkNode( LEQ, range, NodeManager::currentNM()->mkConst( Rational( 9999 ) ) ) );
 296         d_domain[ii].clear();
 297         Node tl = l;
 298         Node tu = u;
 299         if( d_qe->getBoundedIntegers() && d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][ii] ) ){
 300           d_qe->getBoundedIntegers()->getBounds( d_owner, d_owner[0][ii], this, tl, tu );
 301         }
 302         d_lower_bounds[ii] = tl;
 303         if( !actual_l.isNull() ){
 304           //if bound was limited externally, must consider the offset
 305           d_lower_bounds[ii] = Rewriter::rewrite( NodeManager::currentNM()->mkNode( PLUS, tl, actual_l ) );
 306         }
 307         if( ra==NodeManager::currentNM()->mkConst(true) ){
 308           long rr = range.getConst<Rational>().getNumerator().getLong()+1;
 309           Trace("bound-int-rsi")  << "Actual bound range is " << rr << std::endl;
 310           d_domain[ii].push_back( (int)rr );
 311         }else{
 312           Trace("fmf-incomplete") << "Incomplete because of integer quantification, bounds are too big for " << d_owner[0][ii] << "." << std::endl;
 313           d_incomplete = true;
 314           d_domain[ii].push_back( 0 );
 315         }
 316       }
 317     }else{
 318       Trace("bound-int-rsi") << d_owner[0][ii] << " has ground range, skip." << std::endl;
 319     }
 320   }
 321   return true;
 322 }
 323
 324 int RepSetIterator::increment2( int counter ){
 325   Assert( !isFinished() );
 326 #ifdef DISABLE_EVAL_SKIP_MULTIPLE
 327   counter = (int)d_index.size()-1;
 328 #endif
 329   //increment d_index
 330   if( counter>=0){
 331     Trace("rsi-debug") << "domain size of " << counter << " is " << domainSize(counter) << std::endl;
 332   }
 333   while( counter>=0 && d_index[counter]>=(int)(domainSize(counter)-1) ){
 334     counter--;
 335     if( counter>=0){
 336       Trace("rsi-debug") << "domain size of " << counter << " is " << domainSize(counter) << std::endl;
 337     }
 338   }
 339   if( counter==-1 ){
 340     d_index.clear();
 341   }else{
 342     d_index[counter]++;
 343     bool emptyDomain = false;
 344     for( int i=(int)d_index.size()-1; i>counter; i-- ){
 345       if (!resetIndex(i)){
 346         break;
 347       }else if( domainSize(i)<=0 ){
 348         emptyDomain = true;
 349       }
 350     }
 351     if( emptyDomain ){
 352       Trace("rsi-debug") << "This is an empty domain, increment again." << std::endl;
 353       return increment();
 354     }
 355   }
 356   return counter;
 357 }
 358
 359 int RepSetIterator::increment(){
 360   if( !isFinished() ){
 361     return increment2( (int)d_index.size()-1 );
 362   }else{
 363     return -1;
 364   }
 365 }
 366
 367 bool RepSetIterator::isFinished(){
 368   return d_index.empty();
 369 }
 370
 371 Node RepSetIterator::getTerm( int i ){
 372   int index = d_index_order[i];
 373   if( d_enum_type[index]==ENUM_DOMAIN_ELEMENTS ){
 374     TypeNode tn = d_types[index];
 375     Assert( d_rep_set->d_type_reps.find( tn )!=d_rep_set->d_type_reps.end() );
 376     return d_rep_set->d_type_reps[tn][d_domain[index][d_index[index]]];
 377   }else{
 378     Trace("rsi-debug") << "Get, with offset : " << index << " " << d_lower_bounds[index] << " " << d_index[index] << std::endl;
 379     Node t = NodeManager::currentNM()->mkNode(PLUS, d_lower_bounds[index],
 380                                                     NodeManager::currentNM()->mkConst( Rational(d_index[index]) ) );
 381     t = Rewriter::rewrite( t );
 382     return t;
 383   }
 384 }
 385
 386 void RepSetIterator::debugPrint( const char* c ){
 387   for( int i=0; i<(int)d_index.size(); i++ ){
 388     Debug( c ) << i << " : " << d_index[i] << " : " << getTerm( i ) << std::endl;
 389   }
 390 }
 391
 392 void RepSetIterator::debugPrintSmall( const char* c ){
 393   Debug( c ) << "RI: ";
 394   for( int i=0; i<(int)d_index.size(); i++ ){
 395     Debug( c ) << d_index[i] << ": " << getTerm( i ) << " ";
 396   }
 397   Debug( c ) << std::endl;
 398 }