void
HCComponent::iterationInternalLiterals(
vector< Literal >& assumptions )
{
bool hasToAddClause = true;
Clause* clause = new Clause();
for( unsigned int i = 0; i < hcVariables.size(); i++ )
{
Literal lit = Literal( hcVariables[ i ], NEGATIVE );
if( solver.isFalse( hcVariables[ i ] ) )
assumptions.push_back( lit );
else
{
unfoundedSetCandidates.push_back( lit );
if( !hasToAddClause )
continue;
hasToAddClause = addLiteralInClause( lit, clause );
}
}
if( hasToAddClause && literalToAdd != Literal::null )
hasToAddClause = addLiteralInClause( literalToAdd, clause );
if( !hasToAddClause )
{
delete clause;
return;
}
Var addedVar = addFreshVariable();
assumptionLiteral = Literal( addedVar, POSITIVE );
clause->addLiteral( assumptionLiteral.getOppositeLiteral() );
assumptions.push_back( assumptionLiteral );
trace_msg( modelchecker, 2, "Adding clause " << *clause );
#ifndef NDEBUG
bool result =
#endif
checker.addClauseRuntime( clause );
assert( result );
statistics( &checker, assumptionsOR( clause->size() ) );
trace_msg( modelchecker, 3, "Adding " << assumptionLiteral << " as assumption" );
}
/**
* Generate and print a random clause with nbLiterals literals
* @param f the formula
* @param clauseNumber : the clause to generate
* @param : the number of literals that contain the clause
*/
void generateClause(Formula * f, int nbLiterals) {
Clause * c;
createClause(&c);
addClause(f,c);
for(int i = 0;i<nbLiterals;i++) {
int sign = rand()%2 ? 1 : -1;
Literal l = sign*(rand()%f->nbVariables+1);
addLiteralInClause(*f,c,l);
}
}
void
HCComponent::createInitialClauseAndSimplifyHCVars()
{
trace_msg( modelchecker, 1, "Simplifying Head Cycle variables" );
Clause* clause = new Clause();
bool satisfied = false;
int j = 0;
for( unsigned int i = 0; i < hcVariables.size(); i++ )
{
Var v = hcVariables[ j ] = hcVariables[ i ];
if( solver.isTrue( v ) && solver.getDecisionLevel( v ) == 0 )
{
Literal lit = Literal( v, NEGATIVE );
unfoundedSetCandidates.push_back( lit );
removedHCVars++;
trace_msg( modelchecker, 2, "Variable " << Literal( v ) << " is true at level 0: removed" );
if( !satisfied )
satisfied = !addLiteralInClause( lit, clause );
}
else
j++;
}
hcVariables.resize( j );
trace_msg( modelchecker, 2, "Clause before adding a fresh variable " << *clause << ", which is " << ( satisfied ? "" : "not" ) << " satisfied");
if( clause->size() == 0 || satisfied )
{
trace_msg( modelchecker, 3, "Removed" );
delete clause;
}
else
{
statistics( &checker, setTrueAtLevelZero( removedHCVars ) );
assert( clause != NULL );
Var newVar = addFreshVariable();
literalToAdd = Literal( newVar, NEGATIVE );
clause->addLiteral( literalToAdd.getOppositeLiteral() );
trace_msg( modelchecker, 3, "Clause to add " << *clause );
if( !isConflictual )
isConflictual = !checker.addClauseRuntime( clause );
}
assert( removedHCVars == unfoundedSetCandidates.size() );
}
