Examples with ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver com.sri.ai.grinder.theory.differencearithmetic.ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver used on opensource projects

Example 1 with ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver

use of com.sri.ai.grinder.theory.differencearithmetic.ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver in project aic-expresso by aic-sri-international.

the class AssignmentsSamplingIterator method getTypeToSampleFrom.

public static Type getTypeToSampleFrom(Expression variable, Expression condition, Context context) {
    Type result = GrinderUtil.getTypeOfExpression(variable, context);
    if (result instanceof FunctionType) {
        FunctionType functionType = (FunctionType) result;
        result = new LazySampledFunctionType(functionType.getCodomain(), functionType.getArgumentTypes().toArray(new Type[functionType.getArity()]));
    } else {
        if (condition.equals(false)) {
            result = null;
        } else if (condition.equals(true)) {
        // we leave as is.
        } else if (result instanceof RealExpressoType || result instanceof RealInterval) {
            LinearRealArithmeticTheory theory = new LinearRealArithmeticTheory(true, true);
            SingleVariableLinearRealArithmeticConstraint constraint = (SingleVariableLinearRealArithmeticConstraint) theory.makeSingleVariableConstraint(variable, context);
            constraint = (SingleVariableLinearRealArithmeticConstraint) constraint.conjoin(condition, context);
            IntervalWithMeasureEquivalentToSingleVariableLinearRealArithmeticConstraintStepSolver solver = new IntervalWithMeasureEquivalentToSingleVariableLinearRealArithmeticConstraintStepSolver(constraint);
            Expression realInterval = solver.solve(context);
            if (Sets.isEmptySet(realInterval)) {
                // used to indicate an empty set.
                result = null;
            } else if (ExtensionalSets.isExtensionalSet(realInterval) && ExtensionalSets.isSingleton(realInterval)) {
                String singletonValue = realInterval.get(0).toString();
                result = new RealInterval("[" + singletonValue + ";" + singletonValue + "]");
            } else {
                result = new RealInterval(realInterval.toString());
            }
        } else if (result instanceof IntegerExpressoType || result instanceof IntegerInterval) {
            DifferenceArithmeticTheory theory = new DifferenceArithmeticTheory(true, true);
            SingleVariableDifferenceArithmeticConstraint constraint = (SingleVariableDifferenceArithmeticConstraint) theory.makeSingleVariableConstraint(variable, context);
            constraint = (SingleVariableDifferenceArithmeticConstraint) constraint.conjoin(condition, context);
            ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver solver = new ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver(constraint);
            // NOTE: the exceptions set returned here is implicit in the condition so no need to use it here.
            RangeAndExceptionsSet rangeAndExceptionsSet = (RangeAndExceptionsSet) solver.solve(context);
            if (rangeAndExceptionsSet.isEmpty()) {
                // used to indicate an empty set.
                result = null;
            } else if (rangeAndExceptionsSet.isSingleton()) {
                result = new IntegerInterval(rangeAndExceptionsSet.getSingleValue().intValueExact(), rangeAndExceptionsSet.getSingleValue().intValueExact());
            } else {
                result = new IntegerInterval(rangeAndExceptionsSet.getStrictLowerBound().intValueExact() + 1, rangeAndExceptionsSet.getNonStrictUpperBound().intValueExact());
            }
        }
    }
    if (result != null && !result.isSampleUniquelyNamedConstantSupported()) {
        throw new IllegalArgumentException("Unable to sample " + variable + " from " + result);
    }
    return result;
}

Example 2 with ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver

use of com.sri.ai.grinder.theory.differencearithmetic.ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver in project aic-expresso by aic-sri-international.

the class ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolverTest method runTest.

private void runTest(Expression variable, String constraintString, Expression expected, Context context) {
    Constraint constraint = new SingleVariableDifferenceArithmeticConstraint(variable, true, context.getTheory());
    constraint = constraint.conjoin(parse(constraintString), context);
    ExpressionLiteralSplitterStepSolver stepSolver = new ValuesOfSingleVariableDifferenceArithmeticConstraintStepSolver((SingleVariableDifferenceArithmeticConstraint) constraint);
    Expression actual = stepSolver.solve(context);
    System.out.println("Variable " + variable + "\nhas possible values:\n" + actual + "\nsatisfying constraint:\n" + constraintString + "\n");
    assertEquals(expected, actual);
}