src/theory/quantifiers/quant_conflict_find.h

   1 /*********************                                                        */
   2 /*! \file quant_conflict_find.h
   3  ** \verbatim
   4  ** Original author: Andrew Reynolds
   5  ** Major contributors: none
   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 quantifiers conflict find class
  13  **/
  14
  15 #include "cvc4_private.h"
  16
  17 #ifndef QUANT_CONFLICT_FIND
  18 #define QUANT_CONFLICT_FIND
  19
  20 #include "context/cdhashmap.h"
  21 #include "context/cdchunk_list.h"
  22 #include "theory/quantifiers_engine.h"
  23
  24 namespace CVC4 {
  25 namespace theory {
  26 namespace quantifiers {
  27
  28 class QcfNode;
  29
  30 class QuantConflictFind;
  31
  32 class QcfNodeIndex {
  33 public:
  34   std::map< TNode, QcfNodeIndex > d_children;
  35   void clear() { d_children.clear(); }
  36   void debugPrint( const char * c, int t );
  37   Node existsTerm( TNode n, std::vector< TNode >& reps, int index = 0 );
  38   Node addTerm( TNode n, std::vector< TNode >& reps, int index = 0 );
  39 };
  40
  41 class QuantInfo;
  42
  43 //match generator
  44 class MatchGen {
  45   friend class QuantInfo;
  46 private:
  47   //current children information
  48   int d_child_counter;
  49   //children of this object
  50   std::vector< int > d_children_order;
  51   unsigned getNumChildren() { return d_children.size(); }
  52   MatchGen * getChild( int i ) { return &d_children[d_children_order[i]]; }
  53   //MatchGen * getChild( int i ) { return &d_children[i]; }
  54   //current matching information
  55   std::vector< QcfNodeIndex * > d_qn;
  56   std::vector< std::map< TNode, QcfNodeIndex >::iterator > d_qni;
  57   bool doMatching( QuantConflictFind * p, QuantInfo * qi );
  58   //for matching : each index is either a variable or a ground term
  59   unsigned d_qni_size;
  60   std::map< int, int > d_qni_var_num;
  61   std::map< int, TNode > d_qni_gterm;
  62   std::map< int, TNode > d_qni_gterm_rep;
  63   std::map< int, int > d_qni_bound;
  64   std::vector< int > d_qni_bound_except;
  65   std::map< int, TNode > d_qni_bound_cons;
  66   std::map< int, int > d_qni_bound_cons_var;
  67   std::map< int, int >::iterator d_binding_it;
  68   //std::vector< int > d_independent;
  69   bool d_matched_basis;
  70   bool d_binding;
  71   //int getVarBindingVar();
  72   std::map< int, Node > d_ground_eval;
  73   //determine variable order
  74   void determineVariableOrder( QuantInfo * qi, std::vector< int >& bvars );
  75   void collectBoundVar( QuantInfo * qi, Node n, std::vector< int >& cbvars );
  76 public:
  77   //type of the match generator
  78   enum {
  79     typ_invalid,
  80     typ_ground,
  81     typ_pred,
  82     typ_eq,
  83     typ_formula,
  84     typ_var,
  85     typ_ite_var,
  86     typ_bool_var,
  87   };
  88   void debugPrintType( const char * c, short typ, bool isTrace = false );
  89 public:
  90   MatchGen() : d_type( typ_invalid ){}
  91   MatchGen( QuantInfo * qi, Node n, bool isVar = false, bool beneathQuant = false );
  92   bool d_tgt;
  93   bool d_tgt_orig;
  94   bool d_wasSet;
  95   Node d_n;
  96   std::vector< MatchGen > d_children;
  97   short d_type;
  98   bool d_type_not;
  99   void reset_round( QuantConflictFind * p );
 100   void reset( QuantConflictFind * p, bool tgt, QuantInfo * qi );
 101   bool getNextMatch( QuantConflictFind * p, QuantInfo * qi );
 102   bool getExplanation( QuantConflictFind * p, QuantInfo * qi, std::vector< Node >& exp );
 103   Node getExplanationTerm( QuantConflictFind * p, QuantInfo * qi, Node t, std::vector< Node >& exp );
 104   bool isValid() { return d_type!=typ_invalid; }
 105   void setInvalid();
 106
 107   // is this term treated as UF application?
 108   static bool isHandledBoolConnective( TNode n );
 109   static bool isHandledUfTerm( TNode n );
 110   static Node getOperator( QuantConflictFind * p, Node n );
 111   //can this node be handled by the algorithm
 112   static bool isHandled( TNode n );
 113 };
 114
 115 //info for quantifiers
 116 class QuantInfo {
 117 private:
 118   void registerNode( Node n, bool hasPol, bool pol, bool beneathQuant = false );
 119   void flatten( Node n, bool beneathQuant );
 120 private: //for completing match
 121   std::vector< int > d_unassigned;
 122   std::vector< TypeNode > d_unassigned_tn;
 123   int d_unassigned_nvar;
 124   int d_una_index;
 125   std::vector< int > d_una_eqc_count;
 126 public:
 127   QuantInfo() : d_mg( NULL ) {}
 128   ~QuantInfo() { delete d_mg; }
 129   std::vector< TNode > d_vars;
 130   std::map< TNode, int > d_var_num;
 131   std::map< TNode, bool > d_nbeneathQuant;
 132   std::map< int, std::vector< Node > > d_var_constraint[2];
 133   int getVarNum( TNode v ) { return d_var_num.find( v )!=d_var_num.end() ? d_var_num[v] : -1; }
 134   bool isVar( TNode v ) { return d_var_num.find( v )!=d_var_num.end(); }
 135   int getNumVars() { return (int)d_vars.size(); }
 136   TNode getVar( int i ) { return d_vars[i]; }
 137
 138   MatchGen * d_mg;
 139   Node d_q;
 140   std::map< int, MatchGen * > d_var_mg;
 141   void reset_round( QuantConflictFind * p );
 142 public:
 143   //initialize
 144   void initialize( Node q, Node qn );
 145   //current constraints
 146   std::vector< TNode > d_match;
 147   std::vector< TNode > d_match_term;
 148   std::map< int, std::map< TNode, int > > d_curr_var_deq;
 149   int getCurrentRepVar( int v );
 150   TNode getCurrentValue( TNode n );
 151   TNode getCurrentExpValue( TNode n );
 152   bool getCurrentCanBeEqual( QuantConflictFind * p, int v, TNode n, bool chDiseq = false );
 153   int addConstraint( QuantConflictFind * p, int v, TNode n, bool polarity );
 154   int addConstraint( QuantConflictFind * p, int v, TNode n, int vn, bool polarity, bool doRemove );
 155   bool setMatch( QuantConflictFind * p, int v, TNode n );
 156   bool isMatchSpurious( QuantConflictFind * p );
 157   bool completeMatch( QuantConflictFind * p, std::vector< int >& assigned, bool doContinue = false );
 158   void revertMatch( std::vector< int >& assigned );
 159   void debugPrintMatch( const char * c );
 160   bool isConstrainedVar( int v );
 161 public:
 162   void getMatch( std::vector< Node >& terms );
 163 };
 164
 165 class QuantConflictFind : public QuantifiersModule
 166 {
 167   friend class QcfNodeIndex;
 168   friend class MatchGen;
 169   friend class QuantInfo;
 170   typedef context::CDChunkList<Node> NodeList;
 171   typedef context::CDHashMap<Node, bool, NodeHashFunction> NodeBoolMap;
 172 private:
 173   context::Context* d_c;
 174   context::CDO< bool > d_conflict;
 175   bool d_performCheck;
 176   std::vector< Node > d_quant_order;
 177 private:
 178   std::map< Node, Node > d_op_node;
 179   int d_fid_count;
 180   std::map< Node, int > d_fid;
 181   Node mkEqNode( Node a, Node b );
 182 public:  //for ground terms
 183   Node d_true;
 184   Node d_false;
 185 private:
 186   Node evaluateTerm( Node n );
 187   int evaluate( Node n, bool pref = false, bool hasPref = false );
 188 private:
 189   //currently asserted quantifiers
 190   NodeList d_qassert;
 191   std::map< Node, QuantInfo > d_qinfo;
 192 private:  //for equivalence classes
 193   eq::EqualityEngine * getEqualityEngine();
 194   bool areDisequal( Node n1, Node n2 );
 195   bool areEqual( Node n1, Node n2 );
 196   Node getRepresentative( Node n );
 197
 198 /*
 199   class EqcInfo {
 200   public:
 201     EqcInfo( context::Context* c ) : d_diseq( c ) {}
 202     NodeBoolMap d_diseq;
 203     bool isDisequal( Node n ) { return d_diseq.find( n )!=d_diseq.end() && d_diseq[n]; }
 204     void setDisequal( Node n, bool val = true ) { d_diseq[n] = val; }
 205     //NodeBoolMap& getRelEqr( int index ) { return index==0 ? d_rel_eqr_e : d_rel_eqr_d; }
 206   };
 207   std::map< Node, EqcInfo * > d_eqc_info;
 208   EqcInfo * getEqcInfo( Node n, bool doCreate = true );
 209 */
 210   // operator -> index(terms)
 211   std::map< TNode, QcfNodeIndex > d_uf_terms;
 212   // operator -> index(eqc -> terms)
 213   std::map< TNode, QcfNodeIndex > d_eqc_uf_terms;
 214   //get qcf node index
 215   QcfNodeIndex * getQcfNodeIndex( Node eqc, Node f );
 216   QcfNodeIndex * getQcfNodeIndex( Node f );
 217   // type -> list(eqc)
 218   std::map< TypeNode, std::vector< TNode > > d_eqcs;
 219   std::map< TypeNode, Node > d_model_basis;
 220   //mapping from UF terms to representatives of their arguments
 221   std::map< TNode, std::vector< TNode > > d_arg_reps;
 222   //compute arg reps
 223   void computeArgReps( TNode n );
 224   //compute
 225   void computeUfTerms( TNode f );
 226 public:
 227   enum {
 228     effort_conflict,
 229     effort_prop_eq,
 230     effort_mc,
 231   };
 232   short d_effort;
 233   void setEffort( int e ) { d_effort = e; }
 234   static short getMaxQcfEffort();
 235   bool areMatchEqual( TNode n1, TNode n2 );
 236   bool areMatchDisequal( TNode n1, TNode n2 );
 237 public:
 238   QuantConflictFind( QuantifiersEngine * qe, context::Context* c );
 239   /** register quantifier */
 240   void registerQuantifier( Node q );
 241 public:
 242   /** assert quantifier */
 243   void assertNode( Node q );
 244   /** new node */
 245   void newEqClass( Node n );
 246   /** merge */
 247   void merge( Node a, Node b );
 248   /** assert disequal */
 249   void assertDisequal( Node a, Node b );
 250   /** reset round */
 251   void reset_round( Theory::Effort level );
 252   /** check */
 253   void check( Theory::Effort level );
 254   /** needs check */
 255   bool needsCheck( Theory::Effort level );
 256 private:
 257   bool d_needs_computeRelEqr;
 258 public:
 259   void computeRelevantEqr();
 260 private:
 261   void debugPrint( const char * c );
 262   //for debugging
 263   std::vector< Node > d_quants;
 264   std::map< Node, int > d_quant_id;
 265   void debugPrintQuant( const char * c, Node q );
 266   void debugPrintQuantBody( const char * c, Node q, Node n, bool doVarNum = true );
 267 public:
 268   /** statistics class */
 269   class Statistics {
 270   public:
 271     IntStat d_inst_rounds;
 272     IntStat d_conflict_inst;
 273     IntStat d_prop_inst;
 274     Statistics();
 275     ~Statistics();
 276   };
 277   Statistics d_statistics;
 278   /** Identify this module */
 279   std::string identify() const { return "QcfEngine"; }
 280 };
 281
 282 }
 283 }
 284 }
 285
 286 #endif