/*
 * Copyright (c) 1999-2012, Ecole des Mines de Nantes
 * All rights reserved.
 * 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 Ecole des Mines de Nantes 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 REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 */
package solver.constraints.propagators.unary;

import choco.annotations.PropAnn;
import common.ESat;
import solver.constraints.propagators.Propagator;
import solver.constraints.propagators.PropagatorPriority;
import solver.exception.ContradictionException;
import solver.explanations.Deduction;
import solver.explanations.Explanation;
import solver.variables.EventType;
import solver.variables.IntVar;

/**
 * X <= C
 * <br/>
 *
 * @author Charles Prud'homme
 * @since 16/06/11
 */
@PropAnn(tested = PropAnn.Status.EXPLAINED)
public class PropLessOrEqualXC extends Propagator<IntVar> {

    private final int constant;

    public PropLessOrEqualXC(IntVar var, int cste) {
        super(new IntVar[]{var}, PropagatorPriority.UNARY, false);
        this.constant = cste;
    }

    @Override
    public int getPropagationConditions(int vIdx) {
        return EventType.INSTANTIATE.mask + EventType.BOUND.mask;
    }

    @Override
    public void propagate(int evtmask) throws ContradictionException {
        // with views such as abs(...), the prop can be not entailed after initial propagation
        if (vars[0].updateUpperBound(constant, aCause) || vars[0].getUB() <= constant) {
            this.setPassive();
        }
    }

    @Override
    public void propagate(int idxVarInProp, int mask) throws ContradictionException {
        propagate(0);
    }

    @Override
    public ESat isEntailed() {
        return ESat.eval(vars[0].getUB() <= constant);
    }

    @Override
    public String toString() {
        return vars[0].getName() + " <= " + constant;
    }

    @Override
    public void explain(Deduction d, Explanation e) {
        e.add(aCause);
    }
}

@@ -3019,24 +3019,94 @@
     
-return ESat.eval
+if (vars%5B0%5D.getUB() %3C= constant) %7B%0A            return ESat.TRUE;%0A        %7D%0A        if 
 (var
@@ -3105,39 +3105,38 @@
  if (vars%5B0%5D.get
-U
+L
 B() 
-%3C=
+%3E
  constant);%0A    
@@ -3129,16 +3129,89 @@
 onstant)
+ %7B%0A            return ESat.FALSE;%0A        %7D%0A        return ESat.UNDEFINED
 ;%0A    %7D%0A

Fix entailment on X<C