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Example 1 with AbstractSingleVariableConstraintWithDependentNormalizedAtoms

use of com.sri.ai.grinder.sgdpllt.core.constraint.AbstractSingleVariableConstraintWithDependentNormalizedAtoms in project aic-expresso by aic-sri-international.

the class AbstractSingleVariableConstraintWithBinaryAtomsIncludingEquality method conjoinNonTrivialSignAndNormalizedAtomToConstraintWithBoundVariable.

private AbstractSingleVariableConstraintWithDependentNormalizedAtoms conjoinNonTrivialSignAndNormalizedAtomToConstraintWithBoundVariable(boolean sign, Expression normalizedAtom, Context context) {
    Constraint result;
    // first, use super's implementation to detect inconsistencies
    AbstractSingleVariableConstraintWithDependentNormalizedAtoms conjunctionWithSignAndNormalizedAtom = super.conjoinNonTrivialSignAndNormalizedAtom(sign, normalizedAtom, context);
    if (conjunctionWithSignAndNormalizedAtom == null) {
        result = makeContradiction();
    } else {
        // this assumes the original single positive normalized atom stays as the first one in the conjoined constraint
        Expression binding = getPositiveNormalizedAtoms().get(0);
        // create a fresh constraint with the binding and external literals only
        result = makeSimplification(arrayList(binding), arrayList(), getExternalLiterals());
        // apply new normalized atom after replacing constraint's variable by its value (making it an external literal)
        Expression newExternalLiteral = rewriteSignAndNormalizedAtomForValueVariableIsBoundTo(sign, normalizedAtom, binding.get(1), context);
        result = result.conjoinWithLiteral(newExternalLiteral, context);
    }
    return (AbstractSingleVariableConstraintWithDependentNormalizedAtoms) result;
// Note: a simpler, more expensive version of this method could create an empty constraint,
// conjoin it with the binding, with each external literal, and the new normalized atom, converted to external literal,
// as opposed to using makeRefinementWith with all external literals at once.
// That solution would require the application of external literals one by one, however, whereas the above just copies them all at once.
}
Also used : Constraint(com.sri.ai.grinder.sgdpllt.api.Constraint) Expression(com.sri.ai.expresso.api.Expression) AbstractSingleVariableConstraintWithDependentNormalizedAtoms(com.sri.ai.grinder.sgdpllt.core.constraint.AbstractSingleVariableConstraintWithDependentNormalizedAtoms)

Example 2 with AbstractSingleVariableConstraintWithDependentNormalizedAtoms

use of com.sri.ai.grinder.sgdpllt.core.constraint.AbstractSingleVariableConstraintWithDependentNormalizedAtoms in project aic-expresso by aic-sri-international.

the class AbstractSingleVariableConstraintWithBinaryAtomsIncludingEquality method conjoinNonTrivialNormalizedEqualityToConstraintWithNonBoundVariable.

protected AbstractSingleVariableConstraintWithDependentNormalizedAtoms conjoinNonTrivialNormalizedEqualityToConstraintWithNonBoundVariable(boolean sign, Expression normalizedAtom, Context context) {
    Constraint result;
    // first, use super's implementation to detect inconsistencies
    AbstractSingleVariableConstraintWithDependentNormalizedAtoms conjunctionWithSignAndNormalizedAtom = super.conjoinNonTrivialSignAndNormalizedAtom(sign, normalizedAtom, context);
    if (conjunctionWithSignAndNormalizedAtom == null) {
        result = makeContradiction();
    } else {
        Expression binding = normalizedAtom;
        Expression valueVariableIsBoundTo = binding.get(1);
        // create a fresh constraint with the binding only and external literals
        result = makeSimplification(arrayList(binding), arrayList(), getExternalLiterals());
        // convert all other normalized atoms to external literals with valueVariableIsBoundTo standing for constraint's variable
        result = conjoinWithSignAndNormalizedAtomsOnValueVariableIsBoundTo(result, true, in(getPositiveNormalizedAtomsIncludingImplicitOnes(context)), valueVariableIsBoundTo, context);
        if (result != null) {
            result = conjoinWithSignAndNormalizedAtomsOnValueVariableIsBoundTo(result, false, in(getNegativeNormalizedAtomsIncludingImplicitOnes(context)), valueVariableIsBoundTo, context);
        }
    }
    return (AbstractSingleVariableConstraintWithDependentNormalizedAtoms) result;
}
Also used : Constraint(com.sri.ai.grinder.sgdpllt.api.Constraint) Expression(com.sri.ai.expresso.api.Expression) AbstractSingleVariableConstraintWithDependentNormalizedAtoms(com.sri.ai.grinder.sgdpllt.core.constraint.AbstractSingleVariableConstraintWithDependentNormalizedAtoms)

Aggregations

Expression (com.sri.ai.expresso.api.Expression)2 Constraint (com.sri.ai.grinder.sgdpllt.api.Constraint)2 AbstractSingleVariableConstraintWithDependentNormalizedAtoms (com.sri.ai.grinder.sgdpllt.core.constraint.AbstractSingleVariableConstraintWithDependentNormalizedAtoms)2