Examples with Formula org.logicng.formulas.Formula used on opensource projects

Example 11 with Formula

use of org.logicng.formulas.Formula in project LogicNG by logic-ng.

the class FormulaDepthFunction method apply.

@Override
public Integer apply(final Formula formula, final boolean cache) {
    final Object cached = formula.functionCacheEntry(DEPTH);
    if (cached != null) {
        return (Integer) cached;
    }
    final int result;
    if (formula.isAtomicFormula()) {
        result = 0;
    } else {
        int maxDepth = 0;
        for (final Formula op : formula) {
            maxDepth = Math.max(maxDepth, apply(op, cache));
        }
        result = maxDepth + 1;
    }
    if (cache) {
        formula.setFunctionCacheEntry(DEPTH, result);
    }
    return result;
}

Example 12 with Formula

use of org.logicng.formulas.Formula in project LogicNG by logic-ng.

the class LiteralProfileFunction method nonCachingRecursion.

/**
 * Recursive function for the non-caching literal profile computation.
 * @param formula the formula
 * @param map     the literal profile
 */
private static void nonCachingRecursion(final Formula formula, final Map<Literal, Integer> map) {
    if (formula.type() == FType.LITERAL) {
        final Literal lit = (Literal) formula;
        map.merge(lit, 1, Integer::sum);
    } else if (formula.type() == FType.PBC) {
        for (final Literal l : formula.literals()) {
            nonCachingRecursion(l, map);
        }
    } else {
        for (final Formula op : formula) {
            nonCachingRecursion(op, map);
        }
    }
}

Example 13 with Formula

use of org.logicng.formulas.Formula in project LogicNG by logic-ng.

the class MinimumPrimeImplicantFunction method apply.

@Override
public SortedSet<Literal> apply(final Formula formula, final boolean cache) {
    final Formula nnf = formula.nnf();
    final Map<Variable, Literal> newVar2oldLit = new HashMap<>();
    final LiteralSubstitution substitution = new LiteralSubstitution();
    for (final Literal literal : nnf.literals()) {
        final Variable newVar = formula.factory().variable(literal.name() + (literal.phase() ? POS : NEG));
        newVar2oldLit.put(newVar, literal);
        substitution.addSubstitution(literal, newVar);
    }
    final Formula substitued = nnf.transform(substitution);
    final SATSolver solver = MiniSat.miniSat(formula.factory(), MiniSatConfig.builder().cnfMethod(MiniSatConfig.CNFMethod.PG_ON_SOLVER).build());
    solver.add(substitued);
    for (final Literal literal : newVar2oldLit.values()) {
        if (literal.phase() && newVar2oldLit.containsValue(literal.negate())) {
            solver.add(formula.factory().amo(formula.factory().variable(literal.name() + POS), formula.factory().variable(literal.name() + NEG)));
        }
    }
    if (solver.sat() != Tristate.TRUE) {
        return null;
    }
    final Assignment minimumModel = solver.execute(OptimizationFunction.minimize(newVar2oldLit.keySet()));
    final SortedSet<Literal> primeImplicant = new TreeSet<>();
    for (final Variable variable : minimumModel.positiveVariables()) {
        final Literal literal = newVar2oldLit.get(variable);
        if (literal != null) {
            primeImplicant.add(literal);
        }
    }
    return primeImplicant;
}

Example 14 with Formula

use of org.logicng.formulas.Formula in project LogicNG by logic-ng.

the class SubNodeFunction method apply.

@Override
@SuppressWarnings("unchecked")
public LinkedHashSet<Formula> apply(final Formula formula, final boolean cache) {
    final Object cached = formula.functionCacheEntry(SUBFORMULAS);
    if (cached != null) {
        return (LinkedHashSet<Formula>) cached;
    }
    final LinkedHashSet<Formula> result = new LinkedHashSet<>();
    for (final Formula op : formula) {
        if (!result.contains(op)) {
            result.addAll(apply(op, cache));
        }
    }
    result.add(formula);
    if (cache) {
        formula.setFunctionCacheEntry(SUBFORMULAS, result);
    }
    return result;
}

Example 15 with Formula

use of org.logicng.formulas.Formula in project LogicNG by logic-ng.

the class VariableProfileFunction method nonCachingRecursion.

/**
 * Recursive function for the non-caching variable profile computation.
 * @param formula the formula
 * @param map     the variable profile
 */
private static void nonCachingRecursion(final Formula formula, final Map<Variable, Integer> map) {
    if (formula.type() == FType.LITERAL) {
        final Literal lit = (Literal) formula;
        map.merge(lit.variable(), 1, Integer::sum);
    } else if (formula.type() == FType.PBC) {
        for (final Literal l : formula.literals()) {
            nonCachingRecursion(l.variable(), map);
        }
    } else {
        for (final Formula op : formula) {
            nonCachingRecursion(op, map);
        }
    }
}