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): none
   7  ** This file is part of the CVC4 project.
   8  ** Copyright (c) 2009-2013  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   d_tmap[ n ] = (int)d_type_reps[tn].size();
  42   Trace("rsi-debug") << "Add rep #" << d_type_reps[tn].size() << " for " << tn << " : " << n << std::endl;
  43   d_type_reps[tn].push_back( n );
  44 }
  45
  46 int RepSet::getIndexFor( Node n ) const {
  47   std::map< Node, int >::const_iterator it = d_tmap.find( n );
  48   if( it!=d_tmap.end() ){
  49     return it->second;
  50   }else{
  51     return -1;
  52   }
  53 }
  54
  55 void RepSet::complete( TypeNode t ){
  56   if( d_type_complete.find( t )==d_type_complete.end() ){
  57     d_type_complete[t] = true;
  58     TypeEnumerator te(t);
  59     while( !te.isFinished() ){
  60       Node n = *te;
  61       if( std::find( d_type_reps[t].begin(), d_type_reps[t].end(), n )==d_type_reps[t].end() ){
  62         add( t, n );
  63       }
  64       ++te;
  65     }
  66     for( size_t i=0; i<d_type_reps[t].size(); i++ ){
  67       Trace("reps-complete") << d_type_reps[t][i] << " ";
  68     }
  69     Trace("reps-complete") << std::endl;
  70   }
  71 }
  72
  73 void RepSet::toStream(std::ostream& out){
  74 #if 0
  75   for( std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.begin(); it != d_type_reps.end(); ++it ){
  76     out << it->first << " : " << std::endl;
  77     for( int i=0; i<(int)it->second.size(); i++ ){
  78       out << "   " << i << ": " << it->second[i] << std::endl;
  79     }
  80   }
  81 #else
  82   for( std::map< TypeNode, std::vector< Node > >::iterator it = d_type_reps.begin(); it != d_type_reps.end(); ++it ){
  83     if( !it->first.isFunction() && !it->first.isPredicate() ){
  84       out << "(" << it->first << " " << it->second.size();
  85       out << " (";
  86       for( int i=0; i<(int)it->second.size(); i++ ){
  87         if( i>0 ){ out << " "; }
  88         out << it->second[i];
  89       }
  90       out << ")";
  91       out << ")" << std::endl;
  92     }
  93   }
  94 #endif
  95 }
  96
  97
  98 RepSetIterator::RepSetIterator( QuantifiersEngine * qe, RepSet* rs ) : d_qe(qe), d_rep_set( rs ){
  99   d_incomplete = false;
 100 }
 101
 102 int RepSetIterator::domainSize( int i ) {
 103   Assert(i>=0);
 104   if( d_enum_type[i]==ENUM_DOMAIN_ELEMENTS ){
 105     return d_domain[i].size();
 106   }else{
 107     return d_domain[i][0];
 108   }
 109 }
 110
 111 bool RepSetIterator::setQuantifier( Node f ){
 112   Trace("rsi") << "Make rsi for " << f << std::endl;
 113   Assert( d_types.empty() );
 114   //store indicies
 115   for( size_t i=0; i<f[0].getNumChildren(); i++ ){
 116     d_types.push_back( f[0][i].getType() );
 117   }
 118   d_owner = f;
 119   return initialize();
 120 }
 121
 122 bool RepSetIterator::setFunctionDomain( Node op ){
 123   Trace("rsi") << "Make rsi for " << op << std::endl;
 124   Assert( d_types.empty() );
 125   TypeNode tn = op.getType();
 126   for( size_t i=0; i<tn.getNumChildren()-1; i++ ){
 127     d_types.push_back( tn[i] );
 128   }
 129   d_owner = op;
 130   return initialize();
 131 }
 132
 133 bool RepSetIterator::initialize(){
 134   for( size_t i=0; i<d_types.size(); i++ ){
 135     d_index.push_back( 0 );
 136     //store default index order
 137     d_index_order.push_back( i );
 138     d_var_order[i] = i;
 139     //store default domain
 140     d_domain.push_back( RepDomain() );
 141     TypeNode tn = d_types[i];
 142     if( tn.isSort() ){
 143       if( !d_rep_set->hasType( tn ) ){
 144         Node var = NodeManager::currentNM()->mkSkolem( "repSet", tn, "is a variable created by the RepSetIterator" );
 145         Trace("mkVar") << "RepSetIterator:: Make variable " << var << " : " << tn << std::endl;
 146         d_rep_set->add( tn, var );
 147       }
 148     }else if( tn.isInteger() ){
 149       bool inc = false;
 150       //check if it is bound
 151       if( d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers() ){
 152         if( d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][i] ) ){
 153           Trace("bound-int-rsi") << "Rep set iterator: variable #" << i << " is bounded integer." << std::endl;
 154           d_enum_type.push_back( ENUM_RANGE );
 155         }else{
 156           inc = true;
 157         }
 158       }else{
 159         inc = true;
 160       }
 161       if( inc ){
 162         //check if it is otherwise bound
 163         if( d_bounds[0].find(i)!=d_bounds[0].end() && d_bounds[1].find(i)!=d_bounds[1].end() ){
 164           Trace("bound-int-rsi") << "Rep set iterator: variable #" << i << " is bounded." << std::endl;
 165           d_enum_type.push_back( ENUM_RANGE );
 166         }else{
 167           Trace("fmf-incomplete") << "Incomplete because of integer quantification of " << d_owner[0][i] << "." << std::endl;
 168           d_incomplete = true;
 169         }
 170       }
 171     //enumerate if the sort is reasonably small, the upper bound of 1000 is chosen arbitrarily for now
 172     }else if( tn.getCardinality().isFinite() && !tn.getCardinality().isLargeFinite() &&
 173               tn.getCardinality().getFiniteCardinality().toUnsignedInt()<=1000 ){
 174       d_rep_set->complete( tn );
 175     }else{
 176       Trace("fmf-incomplete") << "Incomplete because of quantification of type " << tn << std::endl;
 177       d_incomplete = true;
 178     }
 179     if( d_enum_type.size()<=i ){
 180       d_enum_type.push_back( ENUM_DOMAIN_ELEMENTS );
 181       if( d_rep_set->hasType( tn ) ){
 182         for( size_t j=0; j<d_rep_set->d_type_reps[tn].size(); j++ ){
 183           d_domain[i].push_back( j );
 184         }
 185       }else{
 186         return false;
 187       }
 188     }
 189   }
 190   //must set a variable index order based on bounded integers
 191   if (d_owner.getKind()==FORALL && d_qe && d_qe->getBoundedIntegers()) {
 192     Trace("bound-int-rsi") << "Calculating variable order..." << std::endl;
 193     std::vector< int > varOrder;
 194     for( unsigned i=0; i<d_qe->getBoundedIntegers()->getNumBoundVars(d_owner); i++ ){
 195       varOrder.push_back(d_qe->getBoundedIntegers()->getBoundVarNum(d_owner,i));
 196     }
 197     for( unsigned i=0; i<d_owner[0].getNumChildren(); i++) {
 198       if( !d_qe->getBoundedIntegers()->isBoundVar(d_owner, d_owner[0][i])) {
 199         varOrder.push_back(i);
 200       }
 201     }
 202     Trace("bound-int-rsi") << "Variable order : ";
 203     for( unsigned i=0; i<varOrder.size(); i++) {
 204       Trace("bound-int-rsi") << varOrder[i] << " ";
 205     }
 206     Trace("bound-int-rsi") << std::endl;
 207     std::vector< int > indexOrder;
 208     indexOrder.resize(varOrder.size());
 209     for( unsigned i=0; i<varOrder.size(); i++){
 210       indexOrder[varOrder[i]] = i;
 211     }
 212     Trace("bound-int-rsi") << "Will use index order : ";
 213     for( unsigned i=0; i<indexOrder.size(); i++) {
 214       Trace("bound-int-rsi") << indexOrder[i] << " ";
 215     }
 216     Trace("bound-int-rsi") << std::endl;
 217     setIndexOrder(indexOrder);
 218   }
 219   //now reset the indices
 220   for (unsigned i=0; i<d_index.size(); i++) {
 221     if (!resetIndex(i, true)){
 222       break;
 223     }
 224   }
 225   return true;
 226 }
 227
 228 void RepSetIterator::setIndexOrder( std::vector< int >& indexOrder ){
 229   d_index_order.clear();
 230   d_index_order.insert( d_index_order.begin(), indexOrder.begin(), indexOrder.end() );
 231   //make the d_var_order mapping
 232   for( int i=0; i<(int)d_index_order.size(); i++ ){
 233     d_var_order[d_index_order[i]] = i;
 234   }
 235 }
 236 /*
 237 void RepSetIterator::setDomain( std::vector< RepDomain >& domain ){
 238   d_domain.clear();
 239   d_domain.insert( d_domain.begin(), domain.begin(), domain.end() );
 240   //we are done if a domain is empty
 241   for( int i=0; i<(int)d_domain.size(); i++ ){
 242     if( d_domain[i].empty() ){
 243       d_index.clear();
 244     }
 245   }
 246 }
 247 */
 248 bool RepSetIterator::resetIndex( int i, bool initial ) {
 249   d_index[i] = 0;
 250   int ii = d_index_order[i];
 251   Trace("bound-int-rsi") << "Reset " << i << " " << ii << " " << initial << std::endl;
 252   //determine the current range
 253   if( d_enum_type[ii]==ENUM_RANGE ){
 254     if( initial || ( d_qe->getBoundedIntegers() && !d_qe->getBoundedIntegers()->isGroundRange( d_owner, d_owner[0][ii] ) ) ){
 255       Trace("bound-int-rsi") << "Getting range of " << d_owner[0][ii] << std::endl;
 256       Node actual_l;
 257       Node l, u;
 258       if( d_qe->getBoundedIntegers() && d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][ii] ) ){
 259         d_qe->getBoundedIntegers()->getBoundValues( d_owner, d_owner[0][ii], this, l, u );
 260       }
 261       for( unsigned b=0; b<2; b++ ){
 262         if( d_bounds[b].find(ii)!=d_bounds[b].end() ){
 263           Trace("bound-int-rsi") << "May further limit bound(" << b << ") based on " << d_bounds[b][ii] << std::endl;
 264           if( b==0 && (l.isNull() || d_bounds[b][ii].getConst<Rational>() > l.getConst<Rational>()) ){
 265             if( !l.isNull() ){
 266               //bound was limited externally, record that the value lower bound is not equal to the term lower bound
 267               actual_l = NodeManager::currentNM()->mkNode( MINUS, d_bounds[b][ii], l );
 268             }
 269             l = d_bounds[b][ii];
 270           }else if( b==1 && (u.isNull() || d_bounds[b][ii].getConst<Rational>() <= u.getConst<Rational>()) ){
 271             u = NodeManager::currentNM()->mkNode( MINUS, d_bounds[b][ii],
 272                                                   NodeManager::currentNM()->mkConst( Rational(1) ) );
 273             u = Rewriter::rewrite( u );
 274           }
 275         }
 276       }
 277
 278       if( l.isNull() || u.isNull() ){
 279         //failed, abort the iterator
 280         d_index.clear();
 281         return false;
 282       }else{
 283         Trace("bound-int-rsi") << "Can limit bounds of " << d_owner[0][ii] << " to " << l << "..." << u << std::endl;
 284         Node range = Rewriter::rewrite( NodeManager::currentNM()->mkNode( MINUS, u, l ) );
 285         Node ra = Rewriter::rewrite( NodeManager::currentNM()->mkNode( LEQ, range, NodeManager::currentNM()->mkConst( Rational( 9999 ) ) ) );
 286         d_domain[ii].clear();
 287         Node tl = l;
 288         Node tu = u;
 289         if( d_qe->getBoundedIntegers() && d_qe->getBoundedIntegers()->isBoundVar( d_owner, d_owner[0][ii] ) ){
 290           d_qe->getBoundedIntegers()->getBounds( d_owner, d_owner[0][ii], this, tl, tu );
 291         }
 292         d_lower_bounds[ii] = tl;
 293         if( !actual_l.isNull() ){
 294           //if bound was limited externally, must consider the offset
 295           d_lower_bounds[ii] = Rewriter::rewrite( NodeManager::currentNM()->mkNode( PLUS, tl, actual_l ) );
 296         }
 297         if( ra==NodeManager::currentNM()->mkConst(true) ){
 298           long rr = range.getConst<Rational>().getNumerator().getLong()+1;
 299           Trace("bound-int-rsi")  << "Actual bound range is " << rr << std::endl;
 300           d_domain[ii].push_back( (int)rr );
 301         }else{
 302           Trace("fmf-incomplete") << "Incomplete because of integer quantification, bounds are too big for " << d_owner[0][ii] << "." << std::endl;
 303           d_incomplete = true;
 304           d_domain[ii].push_back( 0 );
 305         }
 306       }
 307     }else{
 308       Trace("bound-int-rsi") << d_owner[0][ii] << " has ground range, skip." << std::endl;
 309     }
 310   }
 311   return true;
 312 }
 313
 314 int RepSetIterator::increment2( int counter ){
 315   Assert( !isFinished() );
 316 #ifdef DISABLE_EVAL_SKIP_MULTIPLE
 317   counter = (int)d_index.size()-1;
 318 #endif
 319   //increment d_index
 320   if( counter>=0){
 321     Trace("rsi-debug") << "domain size of " << counter << " is " << domainSize(counter) << std::endl;
 322   }
 323   while( counter>=0 && d_index[counter]>=(int)(domainSize(counter)-1) ){
 324     counter--;
 325     if( counter>=0){
 326       Trace("rsi-debug") << "domain size of " << counter << " is " << domainSize(counter) << std::endl;
 327     }
 328   }
 329   if( counter==-1 ){
 330     d_index.clear();
 331   }else{
 332     d_index[counter]++;
 333     bool emptyDomain = false;
 334     for( int i=(int)d_index.size()-1; i>counter; i-- ){
 335       if (!resetIndex(i)){
 336         break;
 337       }else if( domainSize(i)<=0 ){
 338         emptyDomain = true;
 339       }
 340     }
 341     if( emptyDomain ){
 342       Trace("rsi-debug") << "This is an empty domain, increment again." << std::endl;
 343       return increment();
 344     }
 345   }
 346   return counter;
 347 }
 348
 349 int RepSetIterator::increment(){
 350   if( !isFinished() ){
 351     return increment2( (int)d_index.size()-1 );
 352   }else{
 353     return -1;
 354   }
 355 }
 356
 357 bool RepSetIterator::isFinished(){
 358   return d_index.empty();
 359 }
 360
 361 Node RepSetIterator::getTerm( int i ){
 362   int index = d_index_order[i];
 363   if( d_enum_type[index]==ENUM_DOMAIN_ELEMENTS ){
 364     TypeNode tn = d_types[index];
 365     Assert( d_rep_set->d_type_reps.find( tn )!=d_rep_set->d_type_reps.end() );
 366     return d_rep_set->d_type_reps[tn][d_domain[index][d_index[index]]];
 367   }else{
 368     Trace("rsi-debug") << "Get, with offset : " << index << " " << d_lower_bounds[index] << " " << d_index[index] << std::endl;
 369     Node t = NodeManager::currentNM()->mkNode(PLUS, d_lower_bounds[index],
 370                                                     NodeManager::currentNM()->mkConst( Rational(d_index[index]) ) );
 371     t = Rewriter::rewrite( t );
 372     return t;
 373   }
 374 }
 375
 376 void RepSetIterator::debugPrint( const char* c ){
 377   for( int i=0; i<(int)d_index.size(); i++ ){
 378     Debug( c ) << i << " : " << d_index[i] << " : " << getTerm( i ) << std::endl;
 379   }
 380 }
 381
 382 void RepSetIterator::debugPrintSmall( const char* c ){
 383   Debug( c ) << "RI: ";
 384   for( int i=0; i<(int)d_index.size(); i++ ){
 385     Debug( c ) << d_index[i] << ": " << getTerm( i ) << " ";
 386   }
 387   Debug( c ) << std::endl;
 388 }