com.sri.ai.grinder.sgdpllt.library.set.CardinalityTopRewriter Maven / Gradle / Ivy

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/*
 * Copyright (c) 2013, SRI International
 * All rights reserved.
 * Licensed under the The BSD 3-Clause License;
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 * 
 * http://opensource.org/licenses/BSD-3-Clause
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of the aic-expresso nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.sri.ai.grinder.sgdpllt.library.set;

import static com.sri.ai.expresso.helper.Expressions.ONE;
import static com.sri.ai.grinder.sgdpllt.library.set.CountingFormulaEquivalentExpressions.getCondition;
import static com.sri.ai.grinder.sgdpllt.library.set.CountingFormulaEquivalentExpressions.getIndexExpressions;
import static com.sri.ai.grinder.sgdpllt.library.set.CountingFormulaEquivalentExpressions.isCountingFormulaEquivalentExpression;
import static com.sri.ai.util.Util.map;

import com.google.common.annotations.Beta;
import com.sri.ai.expresso.api.CountingFormula;
import com.sri.ai.expresso.api.Expression;
import com.sri.ai.expresso.core.ExtensionalIndexExpressionsSet;
import com.sri.ai.grinder.sgdpllt.api.MultiIndexQuantifierEliminator;
import com.sri.ai.grinder.sgdpllt.group.Sum;
import com.sri.ai.grinder.sgdpllt.library.FunctorConstants;
import com.sri.ai.grinder.sgdpllt.rewriter.api.Simplifier;
import com.sri.ai.grinder.sgdpllt.rewriter.api.TopRewriter;
import com.sri.ai.grinder.sgdpllt.rewriter.core.CombiningTopRewriter;
import com.sri.ai.grinder.sgdpllt.rewriter.core.Switch;

/**
 * A {@link TopRewriter} cardinality and counting formulas according to a given {@link MultiIndexQuantifierEliminator}.
 *
 * @author braz
 *
 */
@Beta
public class CardinalityTopRewriter extends CombiningTopRewriter {

	public CardinalityTopRewriter(MultiIndexQuantifierEliminator quantifierEliminator) {
		
		super(
				"Cardinality",
				new Switch<>(
				Switch.FUNCTOR,
				map(
						FunctorConstants.CARDINALITY, 
						simplifierForCountingFormulaEquivalentExpression(quantifierEliminator)
				))
				,
				new Switch<>(
				Switch.SYNTACTIC_FORM_TYPE,
				map(
						CountingFormula.SYNTACTIC_FORM_TYPE, 
						simplifierForCountingFormulaEquivalentExpression(quantifierEliminator)
				))
		);
	}

	private static Simplifier simplifierForCountingFormulaEquivalentExpression(MultiIndexQuantifierEliminator quantifierEliminator) {
		return (e, p) -> {
			Expression result;
			try {
				if (isCountingFormulaEquivalentExpression(e)) {
					ExtensionalIndexExpressionsSet indexExpressions =
							(ExtensionalIndexExpressionsSet) getIndexExpressions(e);
					result =
							quantifierEliminator.solve(
									new Sum(),
									indexExpressions,
									getCondition(e),
									ONE,
									p);
				}
				else {
					result = e;
				}
			}
			catch (IllegalArgumentException exception) {
				result = e;
			}

			return result;
		};
	}
}