Examples with MultiIndexQuantifierEliminator com.sri.ai.grinder.sgdpllt.api.MultiIndexQuantifierEliminator used on opensource projects

Example 1 with MultiIndexQuantifierEliminator

use of com.sri.ai.grinder.sgdpllt.api.MultiIndexQuantifierEliminator in project aic-expresso by aic-sri-international.

the class BruteForceFunctionTheory method getSingleVariableConstraintQuantifierEliminatorStepSolver.

@Override
public ExpressionLiteralSplitterStepSolver getSingleVariableConstraintQuantifierEliminatorStepSolver(AssociativeCommutativeGroup group, SingleVariableConstraint constraint, Expression body, Context context) {
    Expression variable = constraint.getVariable();
    Expression type = GrinderUtil.getTypeExpression(variable, context);
    Expression indexExpression = IndexExpressions.makeIndexExpression(variable, type);
    ExtensionalIndexExpressionsSet indexExpressionsSet = new ExtensionalIndexExpressionsSet(indexExpression);
    MultiIndexQuantifierEliminator quantifierEliminator = new BruteForceMultiIndexQuantifierEliminator(context.getTheory().getTopRewriter());
    Expression solution = quantifierEliminator.solve(group, indexExpressionsSet, constraint, body, context);
    return new ConstantExpressionStepSolver(solution);
}

Example 2 with MultiIndexQuantifierEliminator

use of com.sri.ai.grinder.sgdpllt.api.MultiIndexQuantifierEliminator in project aic-expresso by aic-sri-international.

the class Compilation method compile.

/**
	 * Compiles an expression to a normalized (decision-tree-like) expression.
	 * @param inputExpression
	 * @param mapFromVariableNameToTypeName
	 * @param mapFromCategoricalTypeNameToSizeString
	 * @param additionalTypes
	 * @param solverListener if not null, invoked on solver used for compilation, before and after compilation starts; returned solver on 'before' invocation is used (it may be the same one used as argument, of course).
	 * @return
	 */
public static Expression compile(Expression inputExpression, Theory theory, Map<String, String> mapFromVariableNameToTypeName, Map<String, String> mapFromUniquelyNamedConstantToTypeName, Map<String, String> mapFromCategoricalTypeNameToSizeString, Collection<Type> additionalTypes, Function<MultiIndexQuantifierEliminator, MultiIndexQuantifierEliminator> solverListener) {
    // the group actually does not matter, because we are not going to have any indices.
    AssociativeCommutativeGroup group = new Max();
    // The solver for the parameters above.
    MultiIndexQuantifierEliminator solver = new SGDPLLT();
    if (solverListener != null) {
        solver = solverListener.apply(solver);
    }
    // We use the Prolog convention of small-letter initials for constants, but we need an exception for the random variables.
    Predicate<Expression> isPrologConstant = new PrologConstantPredicate();
    Predicate<Expression> isUniquelyNamedConstantPredicate = e -> isPrologConstant.apply(e) && !mapFromVariableNameToTypeName.containsKey(e);
    Map<String, String> mapFromSymbolNameToTypeName = new LinkedHashMap<>(mapFromVariableNameToTypeName);
    mapFromSymbolNameToTypeName.putAll(mapFromUniquelyNamedConstantToTypeName);
    // Solve the problem.
    // no indices; we want to keep all variables
    List<Expression> indices = Util.list();
    Expression result = solver.solve(group, inputExpression, indices, mapFromSymbolNameToTypeName, mapFromCategoricalTypeNameToSizeString, additionalTypes, isUniquelyNamedConstantPredicate, theory);
    if (solverListener != null) {
        solverListener.apply(null);
    }
    return result;
}

Example 3 with MultiIndexQuantifierEliminator

use of com.sri.ai.grinder.sgdpllt.api.MultiIndexQuantifierEliminator in project aic-praise by aic-sri-international.

the class TranslationOfTableToInequalities method constructGenericTableExpressionUsingInequalities.

/**
	 * Returns an {@link Expression} equivalent to a given {@link FunctionTable} but in the form of a decision tree
	 * (so hopefully more compact) using inequalities.
	 * @param functionTable
	 * @param solverListener if not null, invoked on solver used for compilation,
	 * before and after compilation is performed; returned solver from "before" invocation is used (it may be the same one used as argument, of course).
	 * @return
	 */
public static Expression constructGenericTableExpressionUsingInequalities(FunctionTable functionTable, Function<MultiIndexQuantifierEliminator, MultiIndexQuantifierEliminator> solverListener) {
    // the strategy in this method is the following:
    // we collect all the contiguous indices sub-sets of the function table sharing their function value.
    // They are kept in a map from each value to a list of indices sub-sets with that value.
    //
    // Then, we sort these groups of indices sub-sets by the sum of their sizes (number of entries), from smallest to largest.
    // This will help us later to create an expression that tests for the largest groups first.
    //
    // Finally, we create an if-then-else expression, starting from the leaf (least common value).
    // For each group of indices sub-sets with the same value, we obtain an inequalities expression describing
    // the conditions for a variable assignment to be in that indices sub-set of the function table.
    // Each portion generates a conjunction, and the group of portions generates a disjunction.
    //
    // The resulting if-then-else expression is linearly organized (only else clauses have nested if-then-else expressions).
    // A more balanced (and thus efficient) representation is obtained by compiling it using SGDPLL(T).
    Map<Double, List<FunctionTableIndicesSubSet>> functionValuesAndCorrespondingIndicesSubSet = map();
    Double currentSubSetFunctionValueIfAny = null;
    List<Integer> firstIndicesOfCurrentSubSetIfAny = null;
    List<Integer> previousIndices = null;
    List<Integer> indices = null;
    CartesianProductEnumeration<Integer> cartesianProduct = new CartesianProductEnumeration<>(UAIUtil.cardinalityValues(functionTable));
    while (cartesianProduct.hasMoreElements()) {
        previousIndices = indices;
        indices = new ArrayList<>(cartesianProduct.nextElement());
        Double functionValue = Math.round(functionTable.entryFor(indices) * 100) / 100.0;
        boolean hitNewFunctionValue = currentSubSetFunctionValueIfAny == null || !functionValue.equals(currentSubSetFunctionValueIfAny);
        if (hitNewFunctionValue) {
            storeIndicesSubSetOnAllVariables(functionTable, firstIndicesOfCurrentSubSetIfAny, previousIndices, currentSubSetFunctionValueIfAny, functionValuesAndCorrespondingIndicesSubSet);
            // get information for next indices sub-set
            currentSubSetFunctionValueIfAny = functionValue;
            firstIndicesOfCurrentSubSetIfAny = indices;
        }
    }
    previousIndices = indices;
    storeIndicesSubSetOnAllVariables(functionTable, firstIndicesOfCurrentSubSetIfAny, previousIndices, currentSubSetFunctionValueIfAny, functionValuesAndCorrespondingIndicesSubSet);
    // we sort (by using TreeMap) lists of indices sub-set with the same function value from those with smaller to greater sizes,
    // and form the final expression backwards, thus prioritizing larger sub-sets
    // whose conditions will be more often satisfied and leading to greater simplifications during inference.
    List<Pair<BigInteger, List<FunctionTableIndicesSubSet>>> listOfPairsOfSizeAndListsOfIndicesSubSetsWithSameFunctionValue = new ArrayList<>(functionValuesAndCorrespondingIndicesSubSet.size());
    for (Map.Entry<Double, List<FunctionTableIndicesSubSet>> functionValueAndIndicesSubSet : functionValuesAndCorrespondingIndicesSubSet.entrySet()) {
        List<FunctionTableIndicesSubSet> indicesSubSetsWithSameFunctionValue = functionValueAndIndicesSubSet.getValue();
        BigInteger sumOfSizes = BigInteger.ZERO;
        for (FunctionTableIndicesSubSet indicesSubSet : indicesSubSetsWithSameFunctionValue) {
            sumOfSizes = sumOfSizes.add(indicesSubSet.size());
        }
        listOfPairsOfSizeAndListsOfIndicesSubSetsWithSameFunctionValue.add(Pair.make(sumOfSizes, indicesSubSetsWithSameFunctionValue));
    }
    Collections.sort(listOfPairsOfSizeAndListsOfIndicesSubSetsWithSameFunctionValue, (Comparator<? super Pair<BigInteger, List<FunctionTableIndicesSubSet>>>) (p1, p2) -> p1.first.compareTo(p2.first));
    List<List<FunctionTableIndicesSubSet>> listsOfIndicesSubSetsWithSameFunctionValue = mapIntoList(listOfPairsOfSizeAndListsOfIndicesSubSetsWithSameFunctionValue, p -> p.second);
    Iterator<List<FunctionTableIndicesSubSet>> listsOfIndicesSubSetsWithSameFunctionValueIterator = listsOfIndicesSubSetsWithSameFunctionValue.iterator();
    List<FunctionTableIndicesSubSet> firstListOfIndicesSubSets = listsOfIndicesSubSetsWithSameFunctionValueIterator.next();
    Double valueOfFirstListOfIndicesSubSets = getFirstOrNull(firstListOfIndicesSubSets).getFunctionValue();
    Expression currentExpression = makeSymbol(valueOfFirstListOfIndicesSubSets);
    while (listsOfIndicesSubSetsWithSameFunctionValueIterator.hasNext()) {
        List<FunctionTableIndicesSubSet> indicesSubSetsWithSameFunctionValue = listsOfIndicesSubSetsWithSameFunctionValueIterator.next();
        Expression functionValueOfIndicesSubSetsWithSameFunctionValue = makeSymbol(getFirstOrNull(indicesSubSetsWithSameFunctionValue).getFunctionValue());
        Expression conditionForThisFunctionValue = Or.make(mapIntoList(indicesSubSetsWithSameFunctionValue, TranslationOfTableToInequalities::getInequalitiesExpressionForFunctionTableIndicesSubSet));
        currentExpression = IfThenElse.make(conditionForThisFunctionValue, functionValueOfIndicesSubSetsWithSameFunctionValue, currentExpression);
    }
    return currentExpression;
}

Example 4 with MultiIndexQuantifierEliminator

use of com.sri.ai.grinder.sgdpllt.api.MultiIndexQuantifierEliminator in project aic-praise by aic-sri-international.

the class UAIUtil method constructGenericTableExpressionUsingEqualities.

/**
	 * Returns an {@link Expression} equivalent to a given {@link FunctionTable} but in the form of a decision tree
	 * (so hopefully more compact) using equalities.
	 * @param functionTable
	 * @param solverListener if not null, invoked on solver used for compilation, before and after compilation is performed; returned solver from "before" invocation is used (it may be the same one used as argument, of course).
	 * @return
	 */
public static Expression constructGenericTableExpressionUsingEqualities(FunctionTable functionTable, Function<MultiIndexQuantifierEliminator, MultiIndexQuantifierEliminator> solverListener) {
    StringBuilder table = new StringBuilder();
    CartesianProductEnumeration<Integer> cartesianProduct = new CartesianProductEnumeration<>(cardinalityValues(functionTable));
    int counter = 0;
    while (cartesianProduct.hasMoreElements()) {
        counter++;
        List<Integer> values = cartesianProduct.nextElement();
        Double entryValue = functionTable.entryFor(values);
        if (counter == cartesianProduct.size().intValue()) {
            // i.e. final value
            table.append(entryValue);
        } else {
            table.append("if ");
            for (int i = 0; i < values.size(); i++) {
                if (i > 0) {
                    table.append(" and ");
                }
                String value = genericConstantValueForVariable(values.get(i), i, functionTable.cardinality(i));
                if (value.equals("true")) {
                    table.append(genericVariableName(i));
                } else if (value.equals("false")) {
                    table.append("not " + genericVariableName(i));
                } else {
                    table.append(genericVariableName(i));
                    table.append(" = ");
                    table.append(value);
                }
            }
            table.append(" then ");
            table.append(entryValue);
            table.append(" else ");
        }
    }
    Expression inputExpression = Expressions.parse(table.toString());
    Function<Integer, Integer> cardinalityOfIthVariable = i -> functionTable.cardinality(i);
    Map<String, String> mapFromCategoricalTypeNameToSizeString = new LinkedHashMap<>();
    Map<String, String> mapFromVariableNameToTypeName = new LinkedHashMap<>();
    Map<String, String> mapFromUniquelyNamedConstantToTypeName = new LinkedHashMap<>();
    for (int i = 0; i < functionTable.numberVariables(); i++) {
        String typeName = genericTypeNameForVariable(i, cardinalityOfIthVariable.apply(i));
        mapFromCategoricalTypeNameToSizeString.put(typeName, "" + cardinalityOfIthVariable.apply(i));
        mapFromVariableNameToTypeName.put(genericVariableName(i), typeName);
        for (int j = 0; j != functionTable.cardinality(i); j++) {
            String jThConstant = genericConstantValueForVariable(j, i, functionTable.cardinality(i));
            mapFromUniquelyNamedConstantToTypeName.put(jThConstant, typeName);
        }
    }
    com.sri.ai.grinder.sgdpllt.api.Theory theory = new EqualityTheory(true, true);
    Expression result = Compilation.compile(inputExpression, theory, mapFromVariableNameToTypeName, mapFromUniquelyNamedConstantToTypeName, mapFromCategoricalTypeNameToSizeString, list(), solverListener);
    return result;
}