Examples with BinaryFormula kodkod.ast.BinaryFormula used on opensource projects

Example 1 with BinaryFormula

use of kodkod.ast.BinaryFormula in project org.alloytools.alloy by AlloyTools.

the class Nodes method roots.

/**
 * Returns the roots of the given formula. In other words, breaks up the given
 * formula into its conjunctive components, {f0, ..., fk}, such that, for all
 * 0<=i<=k, f<sub>i</sub> is not a conjunction and [[f0 && ... && fk]] <=>
 * [[formula]].
 *
 * @return subformulas, {f0, ..., fk}, of the given formula such that, for all
 *         0<=i<=k, f<sub>i</sub> is not a conjuction and [[f0 && ... && fk]]
 *         <=> [[formula]].
 */
public static Set<Formula> roots(Formula formula) {
    final List<Formula> formulas = new LinkedList<Formula>();
    formulas.add(formula);
    final ListIterator<Formula> itr = formulas.listIterator();
    while (itr.hasNext()) {
        final Formula f = itr.next();
        if (f instanceof BinaryFormula) {
            final BinaryFormula bin = (BinaryFormula) f;
            if (bin.op() == FormulaOperator.AND) {
                itr.remove();
                itr.add(bin.left());
                itr.add(bin.right());
                itr.previous();
                itr.previous();
            }
        } else if (f instanceof NaryFormula) {
            final NaryFormula nf = (NaryFormula) f;
            if (nf.op() == FormulaOperator.AND) {
                itr.remove();
                for (Formula child : nf) {
                    itr.add(child);
                }
                for (int i = nf.size(); i > 0; i--) {
                    itr.previous();
                }
            }
        }
    }
    return new LinkedHashSet<Formula>(formulas);
}

Example 2 with BinaryFormula

use of kodkod.ast.BinaryFormula in project org.alloytools.alloy by AlloyTools.

the class A4Solution method k2pos.

/**
 * Associates the Kodkod formula to a particular Alloy Expr (if the Kodkod
 * formula is not already associated with an Alloy Expr or Alloy Pos)
 */
Formula k2pos(Formula formula, Expr expr) throws Err {
    if (solved)
        throw new ErrorFatal("Cannot alter the k->pos mapping since solve() has completed.");
    if (formula == null || expr == null || k2pos.containsKey(formula))
        return formula;
    k2pos.put(formula, expr);
    if (formula instanceof BinaryFormula) {
        BinaryFormula b = (BinaryFormula) formula;
        if (b.op() == FormulaOperator.AND) {
            k2pos(b.left(), expr);
            k2pos(b.right(), expr);
        }
    }
    return formula;
}

Example 3 with BinaryFormula

use of kodkod.ast.BinaryFormula in project org.alloytools.alloy by AlloyTools.

the class A4Solution method k2pos.

/**
 * Associates the Kodkod formula to a particular Alloy Pos (if the Kodkod
 * formula is not already associated with an Alloy Expr or Alloy Pos)
 */
Formula k2pos(Formula formula, Pos pos) throws Err {
    if (solved)
        throw new ErrorFatal("Cannot alter the k->pos mapping since solve() has completed.");
    if (formula == null || pos == null || pos == Pos.UNKNOWN || k2pos.containsKey(formula))
        return formula;
    k2pos.put(formula, pos);
    if (formula instanceof BinaryFormula) {
        BinaryFormula b = (BinaryFormula) formula;
        if (b.op() == FormulaOperator.AND) {
            k2pos(b.left(), pos);
            k2pos(b.right(), pos);
        }
    }
    return formula;
}

Example 4 with BinaryFormula

use of kodkod.ast.BinaryFormula in project org.alloytools.alloy by AlloyTools.

the class FullNegationPropagator method visit.

/**
 * Visits the formula's children with appropriate settings for the negated flag
 * if bf has not been visited before.
 *
 * @see kodkod.ast.visitor.AbstractVoidVisitor#visit(kodkod.ast.BinaryFormula)
 */
@Override
public final void visit(BinaryFormula bf) {
    if (visited(bf))
        return;
    final FormulaOperator op = bf.op();
    switch(op) {
        case AND:
            if (!negated) {
                // left && right
                bf.left().accept(this);
                bf.right().accept(this);
            } else {
                // !(left && right) --> !left || !right
                FullNegationPropagator fne1 = new FullNegationPropagator(shared, annotations);
                bf.left().not().accept(fne1);
                FullNegationPropagator fne2 = new FullNegationPropagator(shared, annotations);
                bf.right().not().accept(fne2);
                addConjunct(Formula.and(fne1.conjuncts).or(Formula.and(fne2.conjuncts)), false, bf);
                hasChanged = true;
            }
            break;
        case OR:
            if (!negated) {
                // left || right
                FullNegationPropagator fne1 = new FullNegationPropagator(shared, annotations);
                bf.left().accept(fne1);
                FullNegationPropagator fne2 = new FullNegationPropagator(shared, annotations);
                bf.right().accept(fne2);
                if (!fne1.hasChanged && !fne2.hasChanged) {
                    addConjunct(bf);
                } else {
                    addConjunct(Formula.and(fne1.conjuncts).or(Formula.and(fne2.conjuncts)), false, bf);
                    hasChanged = true;
                }
            } else {
                // !(left || right) --> !left && !right
                bf.left().accept(this);
                bf.right().accept(this);
                hasChanged = true;
            }
            break;
        case IMPLIES:
            if (!negated) {
                // left => right --> !left || right
                FullNegationPropagator fne1 = new FullNegationPropagator(shared, annotations);
                bf.left().not().accept(fne1);
                FullNegationPropagator fne2 = new FullNegationPropagator(shared, annotations);
                bf.right().accept(fne2);
                addConjunct(Formula.and(fne1.conjuncts).or(Formula.and(fne2.conjuncts)), false, bf);
            } else {
                // !(left => right) --> left && !right
                negated = false;
                bf.left().accept(this);
                negated = true;
                bf.right().accept(this);
            }
            hasChanged = true;
            break;
        case IFF:
            FullNegationPropagator fne1 = new FullNegationPropagator(shared, annotations);
            FullNegationPropagator fne2 = new FullNegationPropagator(shared, annotations);
            if (!negated) {
                // a <=> b --> (a && b) || (!a && !b)
                bf.left().and(bf.right()).accept(fne1);
                bf.left().not().and(bf.right().not()).accept(fne2);
            } else {
                // !(a = b) --> (a && !b) || (!a && b)
                Formula orLhs = bf.left().and(bf.right().not());
                orLhs.accept(fne1);
                Formula orRhs = bf.left().not().and(bf.right());
                orRhs.accept(fne2);
            }
            addConjunct(Formula.and(fne1.conjuncts).or(Formula.and(fne2.conjuncts)), false, bf);
            hasChanged = true;
            break;
        default:
            addConjunct(bf);
    }
}

Example 5 with BinaryFormula

use of kodkod.ast.BinaryFormula in project org.alloytools.alloy by AlloyTools.

the class PrenexNFConverter method visit.

@Override
public Formula visit(BinaryFormula bf) {
    Formula ans;
    switch(bf.op()) {
        case AND:
        case OR:
            Formula left = bf.left().accept(this);
            Formula right = bf.right().accept(this);
            Pair p = new Pair(left, right);
            if (p.hasNoQuant() && left == bf.left() && right == bf.right())
                ans = bf;
            else
                ans = p.compose(bf.op());
            break;
        case IMPLIES:
            ans = bf.left().not().or(bf.right()).accept(this);
            break;
        case IFF:
            ans = bf.left().and(bf.right()).or(bf.left().not().and(bf.right().not())).accept(this);
            break;
        default:
            throw new IllegalStateException("Unknown BinaryFormula operator: " + bf.op());
    }
    return saveMapping(ans, bf);
}