Examples with SingleVariableLinearRealArithmeticConstraint com.sri.ai.grinder.theory.linearrealarithmetic.SingleVariableLinearRealArithmeticConstraint used on opensource projects

Example 1 with SingleVariableLinearRealArithmeticConstraint

use of com.sri.ai.grinder.theory.linearrealarithmetic.SingleVariableLinearRealArithmeticConstraint 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 SingleVariableLinearRealArithmeticConstraint

use of com.sri.ai.grinder.theory.linearrealarithmetic.SingleVariableLinearRealArithmeticConstraint in project aic-expresso by aic-sri-international.

the class Measure method constructComponentIntensionalSet.

private static Expression constructComponentIntensionalSet(Type indexType, IntensionalSet intensionalSet, Expression additiveIdentityElement, Context intensionalSetContext) {
    Expression conditionedBody = IfThenElse.make(intensionalSet.getCondition(), intensionalSet.getHead(), additiveIdentityElement);
    Expression componentIndex = Expressions.makeUniqueVariable("C", conditionedBody, intensionalSetContext);
    Expression indexExpression = IndexExpressions.makeIndexExpression(componentIndex, Expressions.parse(indexType.getName()));
    Expression intensionalCondition = Expressions.TRUE;
    // NOTE: handle the REAL cases where an SingleVariableLinearRealArithmeticConstraint is expected.
    if (indexType instanceof RealExpressoType || indexType instanceof RealInterval) {
        SingleVariableLinearRealArithmeticConstraint svlraConstraint = new SingleVariableLinearRealArithmeticConstraint(componentIndex, true, intensionalSetContext.getTheory());
        intensionalCondition = svlraConstraint;
    }
    Expression result = IntensionalSet.make(Sets.isMultiSet(intensionalSet) ? IntensionalSet.MULTI_SET_LABEL : IntensionalSet.UNI_SET_LABEL, new ExtensionalIndexExpressionsSet(Arrays.asList(indexExpression)), componentIndex, intensionalCondition);
    return result;
}

Example 3 with SingleVariableLinearRealArithmeticConstraint

use of com.sri.ai.grinder.theory.linearrealarithmetic.SingleVariableLinearRealArithmeticConstraint in project aic-expresso by aic-sri-international.

the class Measure method get.

public static Rational get(Expression intensionalSetExpression, Context context) {
    Rational result;
    if (Sets.isIntensionalSet(intensionalSetExpression)) {
        IntensionalSet intensionalSet = (IntensionalSet) intensionalSetExpression;
        IndexExpressionsSet indexExpressionsSet = intensionalSet.getIndexExpressions();
        List<Expression> indices = IndexExpressions.getIndices(indexExpressionsSet);
        if (indices.size() == 1) {
            Expression evaluatedResult;
            Expression intensionalSetIndex = indices.get(0);
            Expression intensionalSetHead = intensionalSet.getHead();
            if (!intensionalSetHead.equals(intensionalSetIndex)) {
                throw new UnsupportedOperationException("Index and Head must be the same to calculate the meaure of an Intensional : " + intensionalSet);
            }
            Expression intensionalSetCondition = intensionalSet.getCondition();
            Context intensionalSetContext = context.extendWith(indexExpressionsSet);
            Type indexType = GrinderUtil.getTypeOfExpression(intensionalSetIndex, intensionalSetContext);
            if (intensionalSetCondition.equals(false)) {
                // short circuit known empty sets up front.
                evaluatedResult = Expressions.ZERO;
            } else if (indexType instanceof RealExpressoType || indexType instanceof RealInterval) {
                // NOTE : For Reals can always assume the condition is of this type.
                SingleVariableLinearRealArithmeticConstraint svConstraint = (SingleVariableLinearRealArithmeticConstraint) intensionalSetCondition;
                MeasureOfSingleVariableLinearRealArithmeticConstraintStepSolver realSolver = new MeasureOfSingleVariableLinearRealArithmeticConstraintStepSolver(svConstraint);
                evaluatedResult = realSolver.solve(intensionalSetContext);
            } else if (indexType instanceof FunctionType) {
                if (!intensionalSetCondition.equals(true)) {
                    throw new UnsupportedOperationException("Measure of intensional set with a function type domain currently do not support conditions: " + intensionalSet);
                }
                // measure(co-domain)^measure(domain)
                FunctionType indexFunctionType = (FunctionType) indexType;
                Expression condomainIntensionalSet = constructComponentIntensionalSet(indexFunctionType.getCodomain(), intensionalSet, ZERO, intensionalSetContext);
                Rational codomainMeasure = get(condomainIntensionalSet, intensionalSetContext);
                Rational domainMeasure = Rational.ONE;
                for (Type argDomainType : indexFunctionType.getArgumentTypes()) {
                    Expression argDomainIntensionalSet = constructComponentIntensionalSet(argDomainType, intensionalSet, ZERO, intensionalSetContext);
                    Rational argMeasure = get(argDomainIntensionalSet, intensionalSetContext);
                    domainMeasure = domainMeasure.multiply(argMeasure);
                }
                evaluatedResult = Expressions.makeSymbol(codomainMeasure.pow(domainMeasure.intValueExact()));
            } else if (indexType instanceof TupleType) {
                if (!intensionalSetCondition.equals(true)) {
                    throw new UnsupportedOperationException("Measure of intensional set with a tuple type domain currently do not support conditions: " + intensionalSet);
                }
                // (element_1, ..., element_n) = measure(element_1) * ... * measure(element_n)
                TupleType indexTupleType = (TupleType) indexType;
                Rational elementMeasuresProduct = Rational.ONE;
                for (Type elementType : indexTupleType.getElementTypes()) {
                    Expression elementDomainIntensionalSet = constructComponentIntensionalSet(elementType, intensionalSet, ZERO, intensionalSetContext);
                    Rational elementMeasure = get(elementDomainIntensionalSet, intensionalSetContext);
                    elementMeasuresProduct = elementMeasuresProduct.multiply(elementMeasure);
                }
                evaluatedResult = Expressions.makeSymbol(elementMeasuresProduct);
            } else {
                Expression countingFormula = new DefaultCountingFormula(indexExpressionsSet, intensionalSet.getCondition());
                evaluatedResult = context.getTheory().evaluate(countingFormula, context);
            }
            if (Expressions.isNumber(evaluatedResult)) {
                result = evaluatedResult.rationalValue();
            } else {
                throw new UnsupportedOperationException("Unable to compute a finite measure for: " + intensionalSet + ", got : " + evaluatedResult);
            }
        } else {
            throw new UnsupportedOperationException("Currently only support the measure of single indexed intensional sets: " + intensionalSet);
        }
    } else {
        throw new IllegalArgumentException("Not an intensional set: " + intensionalSetExpression);
    }
    return result;
}

Example 4 with SingleVariableLinearRealArithmeticConstraint

use of com.sri.ai.grinder.theory.linearrealarithmetic.SingleVariableLinearRealArithmeticConstraint in project aic-expresso by aic-sri-international.

the class LinearRealArithmeticTheoryTest method runTest.

/**
 * @param variable
 * @param constraintString
 * @param expected
 * @param computedFunction
 * @param stepSolverMaker
 * @param context
 */
private void runTest(Expression variable, String constraintString, Expression expected, String computedFunction, Function<SingleVariableConstraint, ExpressionStepSolver> stepSolverMaker, Context context) {
    System.out.println("Solving " + computedFunction + " for " + variable + " in " + constraintString);
    SingleVariableConstraint constraint = new SingleVariableLinearRealArithmeticConstraint(variable, true, context.getTheory());
    constraint = constraint.conjoin(parse(constraintString), context);
    ExpressionStepSolver stepSolver = stepSolverMaker.apply(constraint);
    Expression actual = stepSolver.solve(context);
    System.out.println("Variable " + variable + "\nhas " + computedFunction + ":\n" + actual + "\nfor constraint:\n" + constraintString + "\n");
    assertEquals(expected, actual);
}

Example 5 with SingleVariableLinearRealArithmeticConstraint

use of com.sri.ai.grinder.theory.linearrealarithmetic.SingleVariableLinearRealArithmeticConstraint in project aic-expresso by aic-sri-international.

the class AssignmentsSamplingIteratorTest method newSamplingIterator.

private Iterator<Assignment> newSamplingIterator(String indexString, int sampleSize, String conditionString) {
    Expression index = parse(indexString);
    Expression condition = parse(conditionString);
    // Ensure condition of correct type is created
    Type indexType = GrinderUtil.getTypeOfExpression(index, context);
    if (indexType instanceof RealExpressoType || indexType instanceof RealInterval) {
        SingleVariableLinearRealArithmeticConstraint svlraConstraint = new SingleVariableLinearRealArithmeticConstraint(index, true, context.getTheory());
        svlraConstraint = (SingleVariableLinearRealArithmeticConstraint) svlraConstraint.conjoin(condition, context);
        condition = svlraConstraint;
    } else if (indexType instanceof IntegerExpressoType || indexType instanceof IntegerInterval) {
        SingleVariableDifferenceArithmeticConstraint svdaConstraint = new SingleVariableDifferenceArithmeticConstraint(index, true, context.getTheory());
        svdaConstraint = (SingleVariableDifferenceArithmeticConstraint) svdaConstraint.conjoin(condition, context);
        condition = svdaConstraint;
    }
    AssignmentsSamplingIterator samplingIterator = new AssignmentsSamplingIterator(Arrays.asList(index), condition, conditionRewriter, random, context);
    Iterator<Assignment> result = nIterator(sampleSize, samplingIterator);
    return result;
}