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