src/smt/boolean_terms.cpp

   1 /*********************                                                        */
   2 /*! \file boolean_terms.cpp
   3  ** \verbatim
   4  ** Original author: Morgan Deters
   5  ** Major contributors: none
   6  ** Minor contributors (to current version): Andrew Reynolds
   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 [[ Add one-line brief description here ]]
  13  **
  14  ** [[ Add lengthier description here ]]
  15  ** \todo document this file
  16  **/
  17
  18 #include "smt/boolean_terms.h"
  19 #include "smt/smt_engine.h"
  20 #include "theory/theory_engine.h"
  21 #include "theory/theory_model.h"
  22 #include "theory/booleans/boolean_term_conversion_mode.h"
  23 #include "theory/booleans/options.h"
  24 #include "expr/kind.h"
  25 #include "expr/node_manager_attributes.h"
  26 #include "util/ntuple.h"
  27 #include <string>
  28 #include <algorithm>
  29 #include <set>
  30 #include <map>
  31 #include <stack>
  32
  33 using namespace std;
  34 using namespace CVC4::theory;
  35 using namespace CVC4::theory::booleans;
  36
  37 namespace CVC4 {
  38 namespace smt {
  39
  40 BooleanTermConverter::BooleanTermConverter(SmtEngine& smt) :
  41   d_smt(smt),
  42   d_ff(),
  43   d_tt(),
  44   d_ffDt(),
  45   d_ttDt(),
  46   d_varCache(smt.d_userContext),
  47   d_termCache(smt.d_userContext),
  48   d_typeCache(),
  49   d_datatypeCache(),
  50   d_datatypeReverseCache() {
  51
  52   // set up our "false" and "true" conversions based on command-line option
  53   if(options::booleanTermConversionMode() == BOOLEAN_TERM_CONVERT_TO_BITVECTORS ||
  54      options::booleanTermConversionMode() == BOOLEAN_TERM_CONVERT_NATIVE) {
  55     d_ff = NodeManager::currentNM()->mkConst(BitVector(1u, 0u));
  56     d_tt = NodeManager::currentNM()->mkConst(BitVector(1u, 1u));
  57   }
  58   if(options::booleanTermConversionMode() == BOOLEAN_TERM_CONVERT_TO_BITVECTORS) {
  59     d_ffDt = d_ff;
  60     d_ttDt = d_tt;
  61   } else {
  62     Datatype spec("BooleanTerm");
  63     // don't change the order; false is assumed to come first by the model postprocessor
  64     spec.addConstructor(DatatypeConstructor("BT_False"));
  65     spec.addConstructor(DatatypeConstructor("BT_True"));
  66     const Datatype& dt = NodeManager::currentNM()->toExprManager()->mkDatatypeType(spec).getDatatype();
  67     d_ffDt = NodeManager::currentNM()->mkNode(kind::APPLY_CONSTRUCTOR, Node::fromExpr(dt["BT_False"].getConstructor()));
  68     d_ttDt = NodeManager::currentNM()->mkNode(kind::APPLY_CONSTRUCTOR, Node::fromExpr(dt["BT_True"].getConstructor()));
  69     // mark this datatype type as being special for Boolean term conversion
  70     TypeNode::fromType(dt.getDatatypeType()).setAttribute(BooleanTermAttr(), Node::null());
  71     if(options::booleanTermConversionMode() == BOOLEAN_TERM_CONVERT_TO_DATATYPES) {
  72       Assert(d_ff.isNull() && d_tt.isNull());
  73       d_ff = d_ffDt;
  74       d_tt = d_ttDt;
  75     }
  76   }
  77
  78   // assert that we set it up correctly
  79   Assert(!d_ff.isNull() && !d_tt.isNull());
  80   Assert(!d_ffDt.isNull() && !d_ttDt.isNull());
  81   Assert(d_ff != d_tt);
  82   Assert(d_ff.getType() == d_tt.getType());
  83   Assert(d_ffDt != d_ttDt);
  84   Assert(d_ffDt.getType() == d_ttDt.getType());
  85
  86 }/* BooleanTermConverter::BooleanTermConverter() */
  87
  88 static inline bool isBoolean(TNode top, unsigned i) {
  89   switch(top.getKind()) {
  90   case kind::NOT:
  91   case kind::AND:
  92   case kind::IFF:
  93   case kind::IMPLIES:
  94   case kind::OR:
  95   case kind::XOR:
  96   case kind::FORALL:
  97   case kind::EXISTS:
  98   case kind::REWRITE_RULE:
  99   case kind::RR_REWRITE:
 100   case kind::RR_DEDUCTION:
 101   case kind::RR_REDUCTION:
 102   case kind::INST_PATTERN:
 103     return true;
 104
 105   case kind::ITE:
 106     if(i == 0) {
 107       return true;
 108     }
 109     return top.getType().isBoolean();
 110
 111   default:
 112     return false;
 113   }
 114 }
 115
 116 // This function rewrites "in" as an "as"---this is actually expected
 117 // to be for model-substitution, so the "in" is a Boolean-term-converted
 118 // node, and "as" is the original.  See how it's used in function
 119 // handling, below.
 120 //
 121 // Note this isn't the case any longer, and parts of what's below have
 122 // been repurposed for *forward* conversion, meaning this works in either
 123 // direction.
 124 Node BooleanTermConverter::rewriteAs(TNode in, TypeNode as) throw() {
 125   if(in.getType() == as) {
 126     return in;
 127   }
 128   if(in.getType().isBoolean()) {
 129     Assert(d_tt.getType() == as);
 130     return NodeManager::currentNM()->mkNode(kind::ITE, in, d_tt, d_ff);
 131   }
 132   if(as.isBoolean() && in.getType().isBitVector() && in.getType().getBitVectorSize() == 1) {
 133     return NodeManager::currentNM()->mkNode(kind::EQUAL, NodeManager::currentNM()->mkConst(BitVector(1u, 1u)), in);
 134   }
 135   if(in.getType().isDatatype()) {
 136     if(as.isBoolean() && in.getType().hasAttribute(BooleanTermAttr())) {
 137       return NodeManager::currentNM()->mkNode(kind::EQUAL, d_ttDt, in);
 138     }
 139     Assert(as.isDatatype());
 140     const Datatype* dt2 = &as.getDatatype();
 141     const Datatype* dt1;
 142     if(d_datatypeCache.find(dt2) != d_datatypeCache.end()) {
 143       dt1 = d_datatypeCache[dt2];
 144     } else {
 145       dt1 = d_datatypeReverseCache[dt2];
 146     }
 147     Assert(dt1 != NULL, "expected datatype in cache");
 148     Assert(*dt1 == in.getType().getDatatype(), "improper rewriteAs() between datatypes");
 149     Node out;
 150     for(size_t i = 0; i < dt1->getNumConstructors(); ++i) {
 151       DatatypeConstructor ctor = (*dt1)[i];
 152       NodeBuilder<> appctorb(kind::APPLY_CONSTRUCTOR);
 153       appctorb << (*dt2)[i].getConstructor();
 154       for(size_t j = 0; j < ctor.getNumArgs(); ++j) {
 155         appctorb << rewriteAs(NodeManager::currentNM()->mkNode(kind::APPLY_SELECTOR_TOTAL, ctor[j].getSelector(), in), TypeNode::fromType(SelectorType((*dt2)[i][j].getSelector().getType()).getRangeType()));
 156       }
 157       Node appctor = appctorb;
 158       if(i == 0) {
 159         out = appctor;
 160       } else {
 161         Node newOut = NodeManager::currentNM()->mkNode(kind::ITE, ctor.getTester(), appctor, out);
 162         out = newOut;
 163       }
 164     }
 165     return out;
 166   }
 167   if(in.getType().isArray()) {
 168     // convert in to in'
 169     // e.g. in : (Array Int Bool)
 170     // for in' : (Array Int (_ BitVec 1))
 171     // then subs  in  |=>  \array_lambda ( \lambda (x:Int) . [convert (read a' x) x]
 172     Assert(as.isArray());
 173     Assert(as.getArrayIndexType() == in.getType().getArrayIndexType());
 174     Assert(as.getArrayConstituentType() != in.getType().getArrayConstituentType());
 175     Node x = NodeManager::currentNM()->mkBoundVar(as.getArrayIndexType());
 176     Node boundvars = NodeManager::currentNM()->mkNode(kind::BOUND_VAR_LIST, x);
 177     Node sel = NodeManager::currentNM()->mkNode(kind::SELECT, in, x);
 178     Node selprime = rewriteAs(sel, as.getArrayConstituentType());
 179     Node lam = NodeManager::currentNM()->mkNode(kind::LAMBDA, boundvars, selprime);
 180     Node out = NodeManager::currentNM()->mkNode(kind::ARRAY_LAMBDA, lam);
 181     Assert(out.getType() == as);
 182     return out;
 183   }
 184   if(in.getType().isParametricDatatype() &&
 185      in.getType().isInstantiatedDatatype()) {
 186     // We have something here like (Pair Bool Bool)---need to dig inside
 187     // and make it (Pair BV1 BV1)
 188     Assert(as.isParametricDatatype() && as.isInstantiatedDatatype());
 189     const Datatype* dt2 = &as[0].getDatatype();
 190     std::vector<TypeNode> fromParams, toParams;
 191     for(unsigned i = 0; i < dt2->getNumParameters(); ++i) {
 192       fromParams.push_back(TypeNode::fromType(dt2->getParameter(i)));
 193       toParams.push_back(as[i + 1]);
 194     }
 195     const Datatype* dt1;
 196     if(d_datatypeCache.find(dt2) != d_datatypeCache.end()) {
 197       dt1 = d_datatypeCache[dt2];
 198     } else {
 199       dt1 = d_datatypeReverseCache[dt2];
 200     }
 201     Assert(dt1 != NULL, "expected datatype in cache");
 202     Assert(*dt1 == in.getType()[0].getDatatype(), "improper rewriteAs() between datatypes");
 203     Node out;
 204     for(size_t i = 0; i < dt1->getNumConstructors(); ++i) {
 205       DatatypeConstructor ctor = (*dt1)[i];
 206       NodeBuilder<> appctorb(kind::APPLY_CONSTRUCTOR);
 207       appctorb << (*dt2)[i].getConstructor();
 208       for(size_t j = 0; j < ctor.getNumArgs(); ++j) {
 209         TypeNode asType = TypeNode::fromType(SelectorType((*dt2)[i][j].getSelector().getType()).getRangeType());
 210         asType = asType.substitute(fromParams.begin(), fromParams.end(), toParams.begin(), toParams.end());
 211         appctorb << rewriteAs(NodeManager::currentNM()->mkNode(kind::APPLY_SELECTOR_TOTAL, ctor[j].getSelector(), in), asType);
 212       }
 213       Node appctor = appctorb;
 214       if(i == 0) {
 215         out = appctor;
 216       } else {
 217         Node newOut = NodeManager::currentNM()->mkNode(kind::ITE, ctor.getTester(), appctor, out);
 218         out = newOut;
 219       }
 220     }
 221     return out;
 222   }
 223
 224   Unhandled(in);
 225 }
 226
 227 const Datatype& BooleanTermConverter::convertDatatype(const Datatype& dt) throw() {
 228   const Datatype*& out = d_datatypeCache[&dt];
 229   if(out != NULL) {
 230     return *out;
 231   }
 232
 233   Debug("boolean-terms") << "convertDatatype: considering " << dt.getName() << endl;
 234   for(Datatype::const_iterator c = dt.begin(); c != dt.end(); ++c) {
 235     TypeNode t = TypeNode::fromType((*c).getConstructor().getType());
 236     for(TypeNode::const_iterator a = t.begin(); a != t.end(); ++a) {
 237       TypeNode converted = convertType(*a, true);
 238       Debug("boolean-terms") << "GOT: " << converted << ":" << converted.getId() << endl;
 239       if(*a != converted) {
 240         SortConstructorType mySelfType;
 241         set<Type> unresolvedTypes;
 242         if(dt.isParametric()) {
 243           mySelfType = NodeManager::currentNM()->toExprManager()->mkSortConstructor(dt.getName() + "'", dt.getNumParameters());
 244           unresolvedTypes.insert(mySelfType);
 245         }
 246         vector<Datatype> newDtVector;
 247         if(dt.isParametric()) {
 248           newDtVector.push_back(Datatype(dt.getName() + "'", dt.getParameters(), false));
 249         } else {
 250           newDtVector.push_back(Datatype(dt.getName() + "'", false));
 251         }
 252         Datatype& newDt = newDtVector.front();
 253         Debug("boolean-terms") << "found a Boolean arg in constructor " << (*c).getName() << endl;
 254         for(c = dt.begin(); c != dt.end(); ++c) {
 255           DatatypeConstructor ctor((*c).getName() + "'", (*c).getTesterName() + "'");
 256           t = TypeNode::fromType((*c).getConstructor().getType());
 257           for(DatatypeConstructor::const_iterator a = (*c).begin(); a != (*c).end(); ++a) {
 258             Type argType = (*a).getType().getRangeType();
 259             if(argType.isDatatype() && DatatypeType(argType).getDatatype() == dt) {
 260               Debug("boolean-terms") << "argtype " << argType << " is self" << endl;
 261               if(dt.isParametric()) {
 262                 Debug("boolean-terms") << "is-parametric self is " << mySelfType << endl;
 263                 ctor.addArg((*a).getName() + "'", mySelfType.instantiate(DatatypeType(argType).getDatatype().getParameters()));
 264               } else {
 265                 ctor.addArg((*a).getName() + "'", DatatypeSelfType());
 266               }
 267             } else {
 268               Debug("boolean-terms") << "argtype " << argType << " is NOT self" << endl;
 269               converted = convertType(TypeNode::fromType(argType), true);
 270               if(TypeNode::fromType(argType) != converted) {
 271                 ctor.addArg((*a).getName() + "'", converted.toType());
 272               } else {
 273                 ctor.addArg((*a).getName() + "'", argType);
 274               }
 275             }
 276           }
 277           newDt.addConstructor(ctor);
 278         }
 279         vector<DatatypeType> newDttVector =
 280           NodeManager::currentNM()->toExprManager()->mkMutualDatatypeTypes(newDtVector, unresolvedTypes);
 281         DatatypeType& newDtt = newDttVector.front();
 282         const Datatype& newD = newDtt.getDatatype();
 283         for(c = dt.begin(); c != dt.end(); ++c) {
 284           Debug("boolean-terms") << "constructor " << (*c).getConstructor() << ":" << (*c).getConstructor().getType() << " made into " << newD[(*c).getName() + "'"].getConstructor() << ":" << newD[(*c).getName() + "'"].getConstructor().getType() << endl;
 285           Node::fromExpr(newD[(*c).getName() + "'"].getConstructor()).setAttribute(BooleanTermAttr(), Node::fromExpr((*c).getConstructor()));// other attr?
 286           Debug("boolean-terms") << "mapped " << newD[(*c).getName() + "'"].getConstructor() << " to " << (*c).getConstructor() << endl;
 287           d_varCache[Node::fromExpr((*c).getConstructor())] = Node::fromExpr(newD[(*c).getName() + "'"].getConstructor());
 288           d_varCache[Node::fromExpr((*c).getTester())] = Node::fromExpr(newD[(*c).getName() + "'"].getTester());
 289           for(DatatypeConstructor::const_iterator a = (*c).begin(); a != (*c).end(); ++a) {
 290             d_varCache[Node::fromExpr((*a).getSelector())] = Node::fromExpr(newD[(*c).getName() + "'"].getSelector((*a).getName() + "'"));
 291           }
 292         }
 293         out = &newD;
 294         d_datatypeReverseCache[&newD] = &dt;
 295         return newD;
 296       }
 297     }
 298   }
 299
 300   // this is identity; don't need the reverse cache
 301   out = &dt;
 302   return dt;
 303
 304 }/* BooleanTermConverter::convertDatatype() */
 305
 306 TypeNode BooleanTermConverter::convertType(TypeNode type, bool datatypesContext) {
 307   Debug("boolean-terms") << "CONVERT-TYPE[" << type << ":" << type.getId() << ", " << datatypesContext << "]" << endl;
 308   // This function recursively converts the type.
 309   if(type.isBoolean()) {
 310     return datatypesContext ? d_ttDt.getType() : d_tt.getType();
 311   }
 312   const pair<TypeNode, bool> cacheKey(type, datatypesContext);
 313   if(d_typeCache.find(cacheKey) != d_typeCache.end()) {
 314     TypeNode out = d_typeCache[cacheKey];
 315     return out.isNull() ? type : out;
 316   }
 317   TypeNode& outNode = d_typeCache[cacheKey];
 318   if(type.getKind() == kind::DATATYPE_TYPE ||
 319      type.getKind() == kind::PARAMETRIC_DATATYPE) {
 320     bool parametric = (type.getKind() == kind::PARAMETRIC_DATATYPE);
 321     const Datatype& dt = parametric ? type[0].getConst<Datatype>() : type.getConst<Datatype>();
 322     TypeNode out = TypeNode::fromType(convertDatatype(dt).getDatatypeType());
 323     Debug("boolean-terms") << "AFTER, got "<< out << " param:" << parametric << endl;
 324     if(parametric) {
 325       // re-parameterize the translation
 326       vector<TypeNode> params = type.getParamTypes();
 327       for(size_t i = 0; i < params.size(); ++i) {
 328         Debug("boolean-terms") << "in loop, got "<< params[i] << endl;
 329         params[i] = convertType(params[i], true);
 330         Debug("boolean-terms") << "in loop, convert to "<< params[i] << endl;
 331       }
 332       params.insert(params.begin(), out[0]);
 333       out = NodeManager::currentNM()->mkTypeNode(kind::PARAMETRIC_DATATYPE, params);
 334       Debug("boolean-terms") << "got OUT: " << out << endl;
 335     }
 336     if(out != type) {
 337       outNode = out;// cache it
 338       Debug("boolean-terms") << "OUT is same as TYPE" << endl;
 339     } else Debug("boolean-terms") << "OUT is DIFFERENT FROM TYPE" << endl;
 340     return out;
 341   }
 342   if(type.isRecord()) {
 343     const Record& rec = type.getConst<Record>();
 344     vector< pair<string, Type> > flds;
 345     for(Record::const_iterator i = rec.begin(); i != rec.end(); ++i) {
 346       TypeNode converted = convertType(TypeNode::fromType((*i).second), true);
 347       if(TypeNode::fromType((*i).second) != converted) {
 348         flds.push_back(make_pair((*i).first, converted.toType()));
 349       } else {
 350         flds.push_back(*i);
 351       }
 352     }
 353     TypeNode newRec = NodeManager::currentNM()->mkRecordType(Record(flds));
 354     Debug("tuprec") << "converted " << type << " to " << newRec << endl;
 355     if(newRec != type) {
 356       outNode = newRec;// cache it
 357     }
 358     return newRec;
 359   }
 360   if(!type.isSort() && type.getNumChildren() > 0) {
 361     Debug("boolean-terms") << "here at A for " << type << ":" << type.getId() << endl;
 362     // This should handle tuples and arrays ok.
 363     // Might handle function types too, but they can't go
 364     // in other types, so it doesn't matter.
 365     NodeBuilder<> b(type.getKind());
 366     if(type.getMetaKind() == kind::metakind::PARAMETERIZED) {
 367       b << type.getOperator();
 368     }
 369     for(TypeNode::iterator i = type.begin(); i != type.end(); ++i) {
 370       b << convertType(*i, false);
 371     }
 372     TypeNode out = b;
 373     if(out != type) {
 374       outNode = out;// cache it
 375     }
 376     Debug("boolean-terms") << "here at B, returning " << out << ":" << out.getId() << endl;
 377     return out;
 378   }
 379   // leave the cache at Null
 380   return type;
 381 }/* BooleanTermConverter::convertType() */
 382
 383 // look for vars from "vars" that occur in a term-context in n; transfer them to output.
 384 static void collectVarsInTermContext(TNode n, std::set<TNode>& vars, std::set<TNode>& output, bool boolParent, std::hash_set< std::pair<TNode, bool>, PairHashFunction<TNode, bool, TNodeHashFunction, BoolHashFunction> >& alreadySeen) {
 385   if(vars.empty()) {
 386     return;
 387   }
 388   const pair<TNode, bool> cacheKey(n, boolParent);
 389   if(alreadySeen.find(cacheKey) != alreadySeen.end()) {
 390     return;
 391   }
 392   alreadySeen.insert(cacheKey);
 393
 394   if(n.isVar() && vars.find(n) != vars.end() && !boolParent) {
 395     vars.erase(n);
 396     output.insert(n);
 397     if(vars.empty()) {
 398       return;
 399     }
 400   }
 401   for(size_t i = 0; i < n.getNumChildren(); ++i) {
 402     collectVarsInTermContext(n[i], vars, output, isBoolean(n, i), alreadySeen);
 403     if(vars.empty()) {
 404       return;
 405     }
 406   }
 407 }
 408
 409 Node BooleanTermConverter::rewriteBooleanTermsRec(TNode top, theory::TheoryId parentTheory, std::map<TNode, Node>& quantBoolVars) throw() {
 410
 411   stack< triple<TNode, theory::TheoryId, bool> > worklist;
 412   worklist.push(triple<TNode, theory::TheoryId, bool>(top, parentTheory, false));
 413   stack< NodeBuilder<> > result;
 414   result.push(NodeBuilder<>(kind::TUPLE));
 415
 416   NodeManager* nm = NodeManager::currentNM();
 417
 418   while(!worklist.empty()) {
 419     top = worklist.top().first;
 420     parentTheory = worklist.top().second;
 421     bool& childrenPushed = worklist.top().third;
 422
 423     Kind k = top.getKind();
 424     kind::MetaKind mk = top.getMetaKind();
 425
 426     // we only distinguish between datatypes, booleans, and "other", and we
 427     // don't even distinguish datatypes except when in "native" conversion
 428     // mode
 429     if(parentTheory != theory::THEORY_BOOL) {
 430       if(options::booleanTermConversionMode() != BOOLEAN_TERM_CONVERT_NATIVE ||
 431          parentTheory != theory::THEORY_DATATYPES) {
 432         parentTheory = theory::THEORY_BUILTIN;
 433       }
 434     }
 435
 436     if(!childrenPushed) {
 437       Debug("boolean-terms") << "rewriteBooleanTermsRec: " << top << " - parentTheory=" << parentTheory << endl;
 438
 439       BooleanTermVarCache::iterator i = d_varCache.find(top);
 440       if(i != d_varCache.end()) {
 441         result.top() << ((*i).second.isNull() ? Node(top) : (*i).second);
 442         worklist.pop();
 443         goto next_worklist;
 444       }
 445       BooleanTermCache::iterator j = d_termCache.find(pair<Node, theory::TheoryId>(top, parentTheory));
 446       if(j != d_termCache.end()) {
 447         result.top() << ((*j).second.isNull() ? Node(top) : (*j).second);
 448         worklist.pop();
 449         goto next_worklist;
 450       }
 451
 452       if(quantBoolVars.find(top) != quantBoolVars.end()) {
 453         // this Bool variable is quantified over and we're changing it to a BitVector var
 454         if(parentTheory == theory::THEORY_BOOL) {
 455           result.top() << quantBoolVars[top].eqNode(d_tt);
 456         } else {
 457           result.top() << quantBoolVars[top];
 458         }
 459         worklist.pop();
 460         goto next_worklist;
 461       }
 462
 463       if(parentTheory != theory::THEORY_BOOL && top.getType().isBoolean()) {
 464         // still need to rewrite e.g. function applications over boolean
 465         Node topRewritten = rewriteBooleanTermsRec(top, theory::THEORY_BOOL, quantBoolVars);
 466         Node n;
 467         if(parentTheory == theory::THEORY_DATATYPES) {
 468           n = nm->mkNode(kind::ITE, topRewritten, d_ttDt, d_ffDt);
 469         } else {
 470           n = nm->mkNode(kind::ITE, topRewritten, d_tt, d_ff);
 471         }
 472         Debug("boolean-terms") << "constructed ITE: " << n << endl;
 473         result.top() << n;
 474         worklist.pop();
 475         goto next_worklist;
 476       }
 477
 478       if(mk == kind::metakind::CONSTANT) {
 479         if(k == kind::STORE_ALL) {
 480           const ArrayStoreAll& asa = top.getConst<ArrayStoreAll>();
 481           ArrayType arrType = asa.getType();
 482           TypeNode indexType = TypeNode::fromType(arrType.getIndexType());
 483           Type constituentType = arrType.getConstituentType();
 484           if(constituentType.isBoolean()) {
 485             // we have store_all(true) or store_all(false)
 486             // just turn it into store_all(1) or store_all(0)
 487             if(indexType.isBoolean()) {
 488               // change index type to BV(1) also
 489               indexType = d_tt.getType();
 490             }
 491             ArrayStoreAll asaRepl(nm->mkArrayType(indexType, d_tt.getType()).toType(),
 492                                   (asa.getExpr().getConst<bool>() ? d_tt : d_ff).toExpr());
 493             Node n = nm->mkConst(asaRepl);
 494             Debug("boolean-terms") << " returning new store_all: " << n << endl;
 495             result.top() << n;
 496             worklist.pop();
 497             goto next_worklist;
 498           }
 499           if(indexType.isBoolean()) {
 500             // must change index type to BV(1)
 501             indexType = d_tt.getType();
 502             ArrayStoreAll asaRepl(nm->mkArrayType(indexType, TypeNode::fromType(constituentType)).toType(), asa.getExpr());
 503             Node n = nm->mkConst(asaRepl);
 504             Debug("boolean-terms") << " returning new store_all: " << n << endl;
 505             result.top() << n;
 506             worklist.pop();
 507             goto next_worklist;
 508           }
 509         }
 510         result.top() << top;
 511         worklist.pop();
 512         goto next_worklist;
 513       } else if(mk == kind::metakind::VARIABLE) {
 514         TypeNode t = top.getType();
 515         if(t.isFunction()) {
 516           for(unsigned i = 0; i < t.getNumChildren(); ++i) {
 517             TypeNode newType = convertType(t[i], false);
 518             // is this the return type?  (allowed to be Bool)
 519             bool returnType = (i == t.getNumChildren() - 1);
 520             if(newType != t[i] && (!t[i].isBoolean() || !returnType)) {
 521               vector<TypeNode> argTypes = t.getArgTypes();
 522               for(unsigned j = 0; j < argTypes.size(); ++j) {
 523                 argTypes[j] = convertType(argTypes[j], false);
 524               }
 525               TypeNode rangeType = t.getRangeType();
 526               if(!rangeType.isBoolean()) {
 527                 rangeType = convertType(rangeType, false);
 528               }
 529               TypeNode newType = nm->mkFunctionType(argTypes, rangeType);
 530               Node n = nm->mkSkolem(top.getAttribute(expr::VarNameAttr()) + "__boolterm__",
 531                                     newType, "a function introduced by Boolean-term conversion",
 532                                     NodeManager::SKOLEM_EXACT_NAME);
 533               Debug("boolean-terms") << "constructed func: " << n << " of type " << newType << endl;
 534               top.setAttribute(BooleanTermAttr(), n);
 535               NodeBuilder<> boundVarsBuilder(kind::BOUND_VAR_LIST);
 536               NodeBuilder<> bodyBuilder(kind::APPLY_UF);
 537               bodyBuilder << n;
 538               for(unsigned j = 0; j < t.getNumChildren() - 1; ++j) {
 539                 Node var = nm->mkBoundVar(t[j]);
 540                 boundVarsBuilder << var;
 541                 if(t[j] != argTypes[j]) {
 542                   bodyBuilder << rewriteAs(var, argTypes[j]);
 543                 } else {
 544                   bodyBuilder << var;
 545                 }
 546               }
 547               Node boundVars = boundVarsBuilder;
 548               Node body = bodyBuilder;
 549               if(t.getRangeType() != rangeType) {
 550                 Node convbody = rewriteAs(body, t.getRangeType());
 551                 body = convbody;
 552               }
 553               Node lam = nm->mkNode(kind::LAMBDA, boundVars, body);
 554               Debug("boolean-terms") << "substituting " << top << " ==> " << lam << endl;
 555               d_smt.d_theoryEngine->getModel()->addSubstitution(top, lam);
 556               d_varCache[top] = n;
 557               result.top() << n;
 558               worklist.pop();
 559               goto next_worklist;
 560             }
 561           }
 562         } else if(t.isArray()) {
 563           TypeNode indexType = convertType(t.getArrayIndexType(), false);
 564           TypeNode constituentType = convertType(t.getArrayConstituentType(), false);
 565           if(indexType != t.getArrayIndexType() && constituentType == t.getArrayConstituentType()) {
 566             TypeNode newType = nm->mkArrayType(indexType, constituentType);
 567             Node n = nm->mkSkolem(top.getAttribute(expr::VarNameAttr()) + "'",
 568                                   newType, "an array variable introduced by Boolean-term conversion",
 569                                   NodeManager::SKOLEM_EXACT_NAME);
 570             top.setAttribute(BooleanTermAttr(), n);
 571             Debug("boolean-terms") << "constructed: " << n << " of type " << newType << endl;
 572             Node n_ff = nm->mkNode(kind::SELECT, n, d_ff);
 573             Node n_tt = nm->mkNode(kind::SELECT, n, d_tt);
 574             Node base = nm->mkConst(ArrayStoreAll(ArrayType(top.getType().toType()), (*TypeEnumerator(n_ff.getType())).toExpr()));
 575             Node repl = nm->mkNode(kind::STORE,
 576                                    nm->mkNode(kind::STORE, base, nm->mkConst(true),
 577                                               n_tt),
 578                                    nm->mkConst(false), n_ff);
 579             Debug("boolean-terms") << "array replacement: " << top << " => " << repl << endl;
 580             d_smt.d_theoryEngine->getModel()->addSubstitution(top, repl);
 581             d_varCache[top] = n;
 582             result.top() << n;
 583             worklist.pop();
 584             goto next_worklist;
 585           } else if(indexType == t.getArrayIndexType() && constituentType != t.getArrayConstituentType()) {
 586             TypeNode newType = nm->mkArrayType(indexType, constituentType);
 587             Node n = nm->mkSkolem(top.getAttribute(expr::VarNameAttr()) + "'",
 588                                   newType, "an array variable introduced by Boolean-term conversion",
 589                                   NodeManager::SKOLEM_EXACT_NAME);
 590             top.setAttribute(BooleanTermAttr(), n);
 591             Debug("boolean-terms") << "constructed: " << n << " of type " << newType << endl;
 592             d_smt.d_theoryEngine->getModel()->addSubstitution(top, n);
 593             d_varCache[top] = n;
 594             result.top() << n;
 595             worklist.pop();
 596             goto next_worklist;
 597           } else if(indexType != t.getArrayIndexType() && constituentType != t.getArrayConstituentType()) {
 598             TypeNode newType = nm->mkArrayType(indexType, constituentType);
 599             Node n = nm->mkSkolem(top.getAttribute(expr::VarNameAttr()) + "'",
 600                                   newType, "an array variable introduced by Boolean-term conversion",
 601                                   NodeManager::SKOLEM_EXACT_NAME);
 602             top.setAttribute(BooleanTermAttr(), n);
 603             Debug("boolean-terms") << "constructed: " << n << " of type " << newType << endl;
 604             Node n_ff = nm->mkNode(kind::SELECT, n, d_ff);
 605             Node n_tt = nm->mkNode(kind::SELECT, n, d_tt);
 606             Node base = nm->mkConst(ArrayStoreAll(ArrayType(top.getType().toType()), nm->mkConst(false).toExpr()));
 607             Node repl = nm->mkNode(kind::STORE,
 608                                    nm->mkNode(kind::STORE, base, nm->mkConst(false),
 609                                               nm->mkNode(kind::EQUAL, n_ff, d_tt)), nm->mkConst(true),
 610                                    nm->mkNode(kind::EQUAL, n_tt, d_tt));
 611             Debug("boolean-terms") << "array replacement: " << top << " => " << repl << endl;
 612             d_smt.d_theoryEngine->getModel()->addSubstitution(top, repl);
 613             d_varCache[top] = n;
 614             result.top() << n;
 615             worklist.pop();
 616             goto next_worklist;
 617           }
 618           d_varCache[top] = Node::null();
 619           result.top() << top;
 620           worklist.pop();
 621           goto next_worklist;
 622         } else if(t.isTuple() || t.isRecord()) {
 623           TypeNode newType = convertType(t, true);
 624           if(t != newType) {
 625             Node n = nm->mkSkolem(top.getAttribute(expr::VarNameAttr()) + "'",
 626                                   newType, "a tuple/record variable introduced by Boolean-term conversion",
 627                                   NodeManager::SKOLEM_EXACT_NAME);
 628             top.setAttribute(BooleanTermAttr(), n);
 629             n.setAttribute(BooleanTermAttr(), top);
 630             Debug("boolean-terms") << "adding subs: " << top << " :=> " << n << endl;
 631             d_smt.d_theoryEngine->getModel()->addSubstitution(top, n);
 632             Debug("boolean-terms") << "constructed: " << n << " of type " << newType << endl;
 633             d_varCache[top] = n;
 634             result.top() << n;
 635             worklist.pop();
 636             goto next_worklist;
 637           }
 638           d_varCache[top] = Node::null();
 639           result.top() << top;
 640           worklist.pop();
 641           goto next_worklist;
 642         } else if(t.isDatatype() || t.isParametricDatatype()) {
 643           Debug("boolean-terms") << "found a var of datatype type" << endl;
 644           TypeNode newT = convertType(t, parentTheory == theory::THEORY_DATATYPES);
 645           if(t != newT) {
 646             Assert(d_varCache.find(top) == d_varCache.end(),
 647                    "Node `%s' already in cache ?!", top.toString().c_str());
 648             Node n = nm->mkSkolem(top.getAttribute(expr::VarNameAttr()) + "'",
 649                                   newT, "a datatype variable introduced by Boolean-term conversion",
 650                                   NodeManager::SKOLEM_EXACT_NAME);
 651             Debug("boolean-terms") << "adding subs: " << top << " :=> " << n << endl;
 652             top.setAttribute(BooleanTermAttr(), n);
 653             d_smt.d_theoryEngine->getModel()->addSubstitution(top, n);
 654             Debug("boolean-terms") << "constructed: " << n << " of type " << newT << endl;
 655             d_varCache[top] = n;
 656             result.top() << n;
 657             worklist.pop();
 658             goto next_worklist;
 659           } else {
 660             d_varCache[top] = Node::null();
 661             result.top() << top;
 662             worklist.pop();
 663             goto next_worklist;
 664           }
 665         } else if(t.isConstructor()) {
 666           Assert(parentTheory != theory::THEORY_BOOL);
 667           Assert(t[t.getNumChildren() - 1].getKind() == kind::DATATYPE_TYPE ||
 668                  t[t.getNumChildren() - 1].getKind() == kind::PARAMETRIC_DATATYPE);
 669           const Datatype& dt = t[t.getNumChildren() - 1].getKind() == kind::DATATYPE_TYPE ?
 670             t[t.getNumChildren() - 1].getConst<Datatype>() :
 671             t[t.getNumChildren() - 1][0].getConst<Datatype>();
 672           TypeNode dt2type = convertType(TypeNode::fromType(dt.getDatatypeType()), parentTheory == theory::THEORY_DATATYPES);
 673           const Datatype& dt2 = (dt2type.getKind() == kind::DATATYPE_TYPE ? dt2type : dt2type[0]).getConst<Datatype>();
 674           if(dt != dt2) {
 675             Assert(d_varCache.find(top) != d_varCache.end(),
 676                    "constructor `%s' not in cache", top.toString().c_str());
 677             result.top() << d_varCache[top].get();
 678             worklist.pop();
 679             goto next_worklist;
 680           }
 681           d_varCache[top] = Node::null();
 682           result.top() << top;
 683           worklist.pop();
 684           goto next_worklist;
 685         } else if(t.isTester() || t.isSelector()) {
 686           Assert(parentTheory != theory::THEORY_BOOL);
 687           const Datatype& dt = t[0].getKind() == kind::DATATYPE_TYPE ?
 688             t[0].getConst<Datatype>() :
 689             t[0][0].getConst<Datatype>();
 690           TypeNode dt2type = convertType(TypeNode::fromType(dt.getDatatypeType()), parentTheory == theory::THEORY_DATATYPES);
 691           const Datatype& dt2 = (dt2type.getKind() == kind::DATATYPE_TYPE ? dt2type : dt2type[0]).getConst<Datatype>();
 692           if(dt != dt2) {
 693             Assert(d_varCache.find(top) != d_varCache.end(),
 694                    "tester or selector `%s' not in cache", top.toString().c_str());
 695             result.top() << d_varCache[top].get();
 696             worklist.pop();
 697             goto next_worklist;
 698           } else {
 699             d_varCache[top] = Node::null();
 700             result.top() << top;
 701             worklist.pop();
 702             goto next_worklist;
 703           }
 704         } else if(!t.isSort() && t.getNumChildren() > 0) {
 705           for(TypeNode::iterator i = t.begin(); i != t.end(); ++i) {
 706             if((*i).isBoolean()) {
 707               vector<TypeNode> argTypes(t.begin(), t.end());
 708               replace(argTypes.begin(), argTypes.end(), *i, d_tt.getType());
 709               TypeNode newType = nm->mkTypeNode(t.getKind(), argTypes);
 710               Node n = nm->mkSkolem(top.getAttribute(expr::VarNameAttr()),
 711                                     newType, "a variable introduced by Boolean-term conversion",
 712                                     NodeManager::SKOLEM_EXACT_NAME);
 713               Debug("boolean-terms") << "constructed: " << n << " of type " << newType << endl;
 714               top.setAttribute(BooleanTermAttr(), n);
 715               d_varCache[top] = n;
 716               result.top() << n;
 717               worklist.pop();
 718               goto next_worklist;
 719             }
 720           }
 721         }
 722         result.top() << top;
 723         worklist.pop();
 724         goto next_worklist;
 725       }
 726       switch(k) {
 727       case kind::INST_ATTRIBUTE:
 728       case kind::BOUND_VAR_LIST:
 729         result.top() << top;
 730         worklist.pop();
 731         goto next_worklist;
 732
 733       case kind::REWRITE_RULE:
 734       case kind::RR_REWRITE:
 735       case kind::RR_DEDUCTION:
 736       case kind::RR_REDUCTION:
 737         // not yet supported
 738         result.top() << top;
 739         worklist.pop();
 740         goto next_worklist;
 741
 742       case kind::FORALL:
 743       case kind::EXISTS: {
 744         Debug("bt") << "looking at quantifier -> " << top << endl;
 745         set<TNode> ourVars;
 746         set<TNode> output;
 747         for(TNode::iterator i = top[0].begin(); i != top[0].end(); ++i) {
 748           if((*i).getType().isBoolean()) {
 749             ourVars.insert(*i);
 750           } else if(convertType((*i).getType(), false) != (*i).getType()) {
 751             output.insert(*i);
 752           }
 753         }
 754         if(ourVars.empty() && output.empty()) {
 755           // Simple case, quantifier doesn't quantify over Boolean vars,
 756           // no special handling needed for quantifier.  Fall through.
 757           Debug("bt") << "- quantifier simple case (1), no Boolean vars bound" << endl;
 758         } else {
 759           hash_set< pair<TNode, bool>, PairHashFunction<TNode, bool, TNodeHashFunction, BoolHashFunction> > alreadySeen;
 760           collectVarsInTermContext(top[1], ourVars, output, true, alreadySeen);
 761           if(output.empty()) {
 762             // Simple case, quantifier quantifies over Boolean vars, but they
 763             // don't occur in term context.  Fall through.
 764             Debug("bt") << "- quantifier simple case (2), Boolean vars bound but not used in term context" << endl;
 765           } else {
 766             Debug("bt") << "- quantifier case (3), Boolean vars bound and used in term context" << endl;
 767             // We have Boolean vars appearing in term context.  Convert their
 768             // types in the quantifier.
 769             for(set<TNode>::const_iterator i = output.begin(); i != output.end(); ++i) {
 770               Node newVar = nm->mkBoundVar((*i).toString(), convertType((*i).getType(), false));
 771               Assert(quantBoolVars.find(*i) == quantBoolVars.end(), "bad quantifier: shares a bound var with another quantifier (don't do that!)");
 772               quantBoolVars[*i] = newVar;
 773             }
 774             vector<TNode> boundVars;
 775             for(TNode::iterator i = top[0].begin(); i != top[0].end(); ++i) {
 776               map<TNode, Node>::const_iterator j = quantBoolVars.find(*i);
 777               if(j == quantBoolVars.end()) {
 778                 boundVars.push_back(*i);
 779               } else {
 780                 boundVars.push_back((*j).second);
 781               }
 782             }
 783             Node boundVarList = nm->mkNode(kind::BOUND_VAR_LIST, boundVars);
 784             Node body = rewriteBooleanTermsRec(top[1], theory::THEORY_BOOL, quantBoolVars);
 785             Node quant = nm->mkNode(top.getKind(), boundVarList, body);
 786             Debug("bt") << "rewrote quantifier to -> " << quant << endl;
 787             d_termCache[make_pair(top, theory::THEORY_BOOL)] = quant;
 788             d_termCache[make_pair(top, theory::THEORY_BUILTIN)] = quant.iteNode(d_tt, d_ff);
 789             d_termCache[make_pair(top, theory::THEORY_DATATYPES)] = quant.iteNode(d_tt, d_ff);
 790             result.top() << quant;
 791             worklist.pop();
 792             goto next_worklist;
 793           }
 794         }
 795         /* intentional fall-through for some cases above */
 796       }
 797
 798       default:
 799         result.push(NodeBuilder<>(k));
 800         Debug("bt") << "looking at: " << top << endl;
 801         // rewrite the operator, as necessary
 802         if(mk == kind::metakind::PARAMETERIZED) {
 803           if(k == kind::RECORD) {
 804             result.top() << convertType(top.getType(), parentTheory == theory::THEORY_DATATYPES);
 805           } else if(k == kind::APPLY_TYPE_ASCRIPTION) {
 806             Node asc = nm->mkConst(AscriptionType(convertType(TypeNode::fromType(top.getOperator().getConst<AscriptionType>().getType()), parentTheory == theory::THEORY_DATATYPES).toType()));
 807             result.top() << asc;
 808             Debug("boolean-terms") << "setting " << top.getOperator() << ":" << top.getOperator().getId() << " to point to " << asc << ":" << asc.getId() << endl;
 809             asc.setAttribute(BooleanTermAttr(), top.getOperator());
 810           } else if(kindToTheoryId(k) != THEORY_BV &&
 811                     k != kind::TUPLE_SELECT &&
 812                     k != kind::TUPLE_UPDATE &&
 813                     k != kind::RECORD_SELECT &&
 814                     k != kind::RECORD_UPDATE &&
 815                     k != kind::DIVISIBLE) {
 816             Debug("bt") << "rewriting: " << top.getOperator() << endl;
 817             result.top() << rewriteBooleanTermsRec(top.getOperator(), theory::THEORY_BUILTIN, quantBoolVars);
 818             Debug("bt") << "got: " << result.top().getOperator() << endl;
 819           } else {
 820             result.top() << top.getOperator();
 821           }
 822         }
 823         // push children
 824         for(int i = top.getNumChildren() - 1; i >= 0; --i) {
 825           Debug("bt") << "rewriting: " << top[i] << endl;
 826           worklist.push(triple<TNode, theory::TheoryId, bool>(top[i], top.getKind() == kind::CHAIN ? parentTheory : (isBoolean(top, i) ? theory::THEORY_BOOL : (top.getKind() == kind::APPLY_CONSTRUCTOR ? theory::THEORY_DATATYPES : theory::THEORY_BUILTIN)), false));
 827           //b << rewriteBooleanTermsRec(top[i], isBoolean(top, i) ? , quantBoolVars);
 828           //Debug("bt") << "got: " << b[b.getNumChildren() - 1] << endl;
 829         }
 830         childrenPushed = true;
 831       }
 832     } else {
 833       Node n = result.top();
 834       result.pop();
 835       Debug("boolean-terms") << "constructed: " << n << endl;
 836       if(parentTheory == theory::THEORY_BOOL) {
 837         if(n.getType().isBitVector() &&
 838            n.getType().getBitVectorSize() == 1) {
 839           n = nm->mkNode(kind::EQUAL, n, d_tt);
 840         } else if(n.getType().isDatatype() &&
 841                   n.getType().hasAttribute(BooleanTermAttr())) {
 842           n = nm->mkNode(kind::EQUAL, n, d_ttDt);
 843         }
 844       }
 845       d_termCache[make_pair(top, parentTheory)] = n;
 846       result.top() << n;
 847       worklist.pop();
 848       goto next_worklist;
 849     }
 850
 851   next_worklist:
 852     ;
 853   }
 854
 855   Assert(worklist.size() == 0);
 856   Assert(result.size() == 1);
 857   Node retval = result.top()[0];
 858   result.top().clear();
 859   result.pop();
 860   return retval;
 861
 862 }/* BooleanTermConverter::rewriteBooleanTermsRec() */
 863
 864 }/* CVC4::smt namespace */
 865 }/* CVC4 namespace */