path: root/src/theory/theory.cpp

/*********************                                                        */
/*! \file theory.cpp
 ** \verbatim
 ** Top contributors (to current version):
 **   Tim King, Dejan Jovanovic, Clark Barrett
 ** This file is part of the CVC4 project.
 ** Copyright (c) 2009-2016 by the authors listed in the file AUTHORS
 ** in the top-level source directory) and their institutional affiliations.
 ** All rights reserved.  See the file COPYING in the top-level source
 ** directory for licensing information.\endverbatim
 **
 ** \brief Base for theory interface.
 **
 ** Base for theory interface.
 **/

#include "theory/theory.h"

#include <vector>
#include <sstream>
#include <iostream>
#include <string>

#include "base/cvc4_assert.h"
#include "smt/smt_statistics_registry.h"
#include "theory/substitutions.h"
#include "theory/quantifiers_engine.h"


using namespace std;

namespace CVC4 {
namespace theory {

/** Default value for the uninterpreted sorts is the UF theory */
TheoryId Theory::s_uninterpretedSortOwner = THEORY_UF;

std::ostream& operator<<(std::ostream& os, Theory::Effort level){
  switch(level){
  case Theory::EFFORT_STANDARD:
    os << "EFFORT_STANDARD"; break;
  case Theory::EFFORT_FULL:
    os << "EFFORT_FULL"; break;
  case Theory::EFFORT_COMBINATION:
    os << "EFFORT_COMBINATION"; break;
  case Theory::EFFORT_LAST_CALL:
    os << "EFFORT_LAST_CALL"; break;
  default:
      Unreachable();
  }
  return os;
}/* ostream& operator<<(ostream&, Theory::Effort) */


Theory::Theory(TheoryId id, context::Context* satContext,
               context::UserContext* userContext, OutputChannel& out,
               Valuation valuation, const LogicInfo& logicInfo,
               std::string name) throw()
    : d_id(id)
    , d_instanceName(name)
    , d_satContext(satContext)
    , d_userContext(userContext)
    , d_logicInfo(logicInfo)
    , d_facts(satContext)
    , d_factsHead(satContext, 0)
    , d_sharedTermsIndex(satContext, 0)
    , d_careGraph(NULL)
    , d_quantEngine(NULL)
    , d_checkTime(getFullInstanceName() + "::checkTime")
    , d_computeCareGraphTime(getFullInstanceName() + "::computeCareGraphTime")
    , d_sharedTerms(satContext)
    , d_out(&out)
    , d_valuation(valuation)
    , d_proofsEnabled(false)
{
  smtStatisticsRegistry()->registerStat(&d_checkTime);
  smtStatisticsRegistry()->registerStat(&d_computeCareGraphTime);
}

Theory::~Theory() {
  smtStatisticsRegistry()->unregisterStat(&d_checkTime);
  smtStatisticsRegistry()->unregisterStat(&d_computeCareGraphTime);
}

TheoryId Theory::theoryOf(TheoryOfMode mode, TNode node) {
  TheoryId tid = THEORY_BUILTIN;
  switch(mode) {
  case THEORY_OF_TYPE_BASED:
    // Constants, variables, 0-ary constructors
    if (node.isVar() || node.isConst()) {
      tid = Theory::theoryOf(node.getType());
    } else if (node.getKind() == kind::EQUAL) {
      // Equality is owned by the theory that owns the domain
      tid = Theory::theoryOf(node[0].getType());
    } else {
      // Regular nodes are owned by the kind
      tid = kindToTheoryId(node.getKind());
    }
    break;
  case THEORY_OF_TERM_BASED:
    // Variables
    if (node.isVar()) {
      if (Theory::theoryOf(node.getType()) != theory::THEORY_BOOL) {
        // We treat the variables as uninterpreted
        tid = s_uninterpretedSortOwner;
      } else {
        // Except for the Boolean ones, which we just ignore anyhow
        tid = theory::THEORY_BOOL;
      }
    } else if (node.isConst()) {
      // Constants go to the theory of the type
      tid = Theory::theoryOf(node.getType());
    } else if (node.getKind() == kind::EQUAL) { // Equality
      // If one of them is an ITE, it's irelevant, since they will get replaced out anyhow
      if (node[0].getKind() == kind::ITE) {
        tid = Theory::theoryOf(node[0].getType());
      } else if (node[1].getKind() == kind::ITE) {
        tid = Theory::theoryOf(node[1].getType());
      } else {
        TNode l = node[0];
        TNode r = node[1];
        TypeNode ltype = l.getType();
        TypeNode rtype = r.getType();
        if( ltype != rtype ){
          tid = Theory::theoryOf(l.getType());
        }else {
          // If both sides belong to the same theory the choice is easy
          TheoryId T1 = Theory::theoryOf(l);
          TheoryId T2 = Theory::theoryOf(r);
          if (T1 == T2) {
            tid = T1;
          } else {
            TheoryId T3 = Theory::theoryOf(ltype);
            // This is a case of
            // * x*y = f(z) -> UF
            // * x = c      -> UF
            // * f(x) = read(a, y) -> either UF or ARRAY
            // at least one of the theories has to be parametric, i.e. theory of the type is different
            // from the theory of the term
            if (T1 == T3) {
              tid = T2;
            } else if (T2 == T3) {
              tid = T1;
            } else {
              // If both are parametric, we take the smaller one (arbitrary)
              tid = T1 < T2 ? T1 : T2;
            }
          }
        }
      }
    } else {
      // Regular nodes are owned by the kind
      tid = kindToTheoryId(node.getKind());
    }
    break;
  default:
    Unreachable();
  }
  Trace("theory::internal") << "theoryOf(" << mode << ", " << node << ") -> " << tid << std::endl;
  return tid;
}

void Theory::addSharedTermInternal(TNode n) {
  Debug("sharing") << "Theory::addSharedTerm<" << getId() << ">(" << n << ")" << endl;
  Debug("theory::assertions") << "Theory::addSharedTerm<" << getId() << ">(" << n << ")" << endl;
  d_sharedTerms.push_back(n);
  addSharedTerm(n);
}

void Theory::computeCareGraph() {
  Debug("sharing") << "Theory::computeCareGraph<" << getId() << ">()" << endl;
  for (unsigned i = 0; i < d_sharedTerms.size(); ++ i) {
    TNode a = d_sharedTerms[i];
    TypeNode aType = a.getType();
    for (unsigned j = i + 1; j < d_sharedTerms.size(); ++ j) {
      TNode b = d_sharedTerms[j];
      if (b.getType() != aType) {
        // We don't care about the terms of different types
        continue;
      }
      switch (d_valuation.getEqualityStatus(a, b)) {
      case EQUALITY_TRUE_AND_PROPAGATED:
      case EQUALITY_FALSE_AND_PROPAGATED:
  	// If we know about it, we should have propagated it, so we can skip
  	break;
      default:
  	// Let's split on it
  	addCarePair(a, b);
  	break;
      }
    }
  }
}

void Theory::printFacts(std::ostream& os) const {
  unsigned i, n = d_facts.size();
  for(i = 0; i < n; i++){
    const Assertion& a_i = d_facts[i];
    Node assertion  = a_i;
    os << d_id << '[' << i << ']' << " " << assertion << endl;
  }
}

void Theory::debugPrintFacts() const{
  DebugChannel.getStream() << "Theory::debugPrintFacts()" << endl;
  printFacts(DebugChannel.getStream());
}

std::hash_set<TNode, TNodeHashFunction> Theory::currentlySharedTerms() const{
  std::hash_set<TNode, TNodeHashFunction> currentlyShared;
  for (shared_terms_iterator i = shared_terms_begin(),
           i_end = shared_terms_end(); i != i_end; ++i) {
    currentlyShared.insert (*i);
  }
  return currentlyShared;
}


void Theory::collectTerms(TNode n, set<Node>& termSet) const
{
  if (termSet.find(n) != termSet.end()) {
    return;
  }
  Trace("theory::collectTerms") << "Theory::collectTerms: adding " << n << endl;
  termSet.insert(n);
  if (n.getKind() == kind::NOT || n.getKind() == kind::EQUAL || !isLeaf(n)) {
    for(TNode::iterator child_it = n.begin(); child_it != n.end(); ++child_it) {
      collectTerms(*child_it, termSet);
    }
  }
}


void Theory::computeRelevantTerms(set<Node>& termSet, bool includeShared) const
{
  // Collect all terms appearing in assertions
  context::CDList<Assertion>::const_iterator assert_it = facts_begin(), assert_it_end = facts_end();
  for (; assert_it != assert_it_end; ++assert_it) {
    collectTerms(*assert_it, termSet);
  }

  if (!includeShared) return;

  // Add terms that are shared terms
  context::CDList<TNode>::const_iterator shared_it = shared_terms_begin(), shared_it_end = shared_terms_end();
  for (; shared_it != shared_it_end; ++shared_it) {
    collectTerms(*shared_it, termSet);
  }
}


Theory::PPAssertStatus Theory::ppAssert(TNode in,
                                        SubstitutionMap& outSubstitutions)
{
  if (in.getKind() == kind::EQUAL) {
    // (and (= x t) phi) can be replaced by phi[x/t] if
    // 1) x is a variable
    // 2) x is not in the term t
    // 3) x : T and t : S, then S <: T
    if (in[0].isVar() && !in[1].hasSubterm(in[0]) &&
        (in[1].getType()).isSubtypeOf(in[0].getType()) ){
      outSubstitutions.addSubstitution(in[0], in[1]);
      return PP_ASSERT_STATUS_SOLVED;
    }
    if (in[1].isVar() && !in[0].hasSubterm(in[1]) &&
        (in[0].getType()).isSubtypeOf(in[1].getType())){
      outSubstitutions.addSubstitution(in[1], in[0]);
      return PP_ASSERT_STATUS_SOLVED;
    }
    if (in[0].isConst() && in[1].isConst()) {
      if (in[0] != in[1]) {
        return PP_ASSERT_STATUS_CONFLICT;
      }
    }
  }

  return PP_ASSERT_STATUS_UNSOLVED;
}

std::pair<bool, Node> Theory::entailmentCheck(
    TNode lit,
    const EntailmentCheckParameters* params,
    EntailmentCheckSideEffects* out) {
  return make_pair(false, Node::null());
}

EntailmentCheckParameters::EntailmentCheckParameters(TheoryId tid)
  : d_tid(tid) {
}

std::string Theory::getFullInstanceName() const {
  std::stringstream ss;
  ss << "theory<" << d_id << ">" << d_instanceName;
  return ss.str();
}

EntailmentCheckParameters::~EntailmentCheckParameters(){}

TheoryId EntailmentCheckParameters::getTheoryId() const {
  return d_tid;
}

EntailmentCheckSideEffects::EntailmentCheckSideEffects(TheoryId tid)
  : d_tid(tid)
{}

TheoryId EntailmentCheckSideEffects::getTheoryId() const {
  return d_tid;
}

EntailmentCheckSideEffects::~EntailmentCheckSideEffects() {
}

}/* CVC4::theory namespace */
}/* CVC4 namespace */