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

Example 56 with Formula

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

the class CNFFactorization method applyRec.

private Formula applyRec(final Formula formula, final boolean cache) {
    if (!this.proceed) {
        return null;
    }
    if (formula.type().precedence() >= LITERAL.precedence()) {
        return formula;
    }
    Formula cached = formula.transformationCacheEntry(FACTORIZED_CNF);
    if (cached != null) {
        return cached;
    }
    switch(formula.type()) {
        case NOT:
        case IMPL:
        case EQUIV:
            cached = this.applyRec(formula.nnf(), cache);
            break;
        case OR:
            LinkedHashSet<Formula> nops = new LinkedHashSet<>();
            for (final Formula op : formula) {
                if (!this.proceed) {
                    return null;
                }
                nops.add(this.applyRec(op, cache));
            }
            final Iterator<Formula> it = nops.iterator();
            cached = it.next();
            while (it.hasNext()) {
                if (!this.proceed) {
                    return null;
                }
                cached = this.distribute(cached, it.next());
            }
            break;
        case AND:
            nops = new LinkedHashSet<>();
            for (final Formula op : formula) {
                final Formula apply = this.applyRec(op, cache);
                if (!this.proceed) {
                    return null;
                }
                nops.add(apply);
            }
            cached = formula.factory().and(nops);
            break;
        case PBC:
            cached = formula.nnf();
            break;
        default:
            throw new IllegalArgumentException("Could not process the formula type " + formula.type());
    }
    if (this.proceed) {
        if (cache) {
            formula.setTransformationCacheEntry(FACTORIZED_CNF, cached);
        }
        return cached;
    }
    return null;
}

Example 57 with Formula

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

the class CNFFactorization method distribute.

/**
 * Computes the distribution (factorization) of two formulas.
 * @param f1 the first formula
 * @param f2 the second formula
 * @return the distribution of the two formulas
 */
private Formula distribute(final Formula f1, final Formula f2) {
    if (this.handler != null) {
        this.proceed = this.handler.performedDistribution();
    }
    if (this.proceed) {
        final FormulaFactory f = f1.factory();
        if (f1.type() == AND || f2.type() == AND) {
            final LinkedHashSet<Formula> nops = new LinkedHashSet<>();
            for (final Formula op : f1.type() == AND ? f1 : f2) {
                final Formula distribute = this.distribute(op, f1.type() == AND ? f2 : f1);
                if (!this.proceed) {
                    return null;
                }
                nops.add(distribute);
            }
            return f.and(nops);
        }
        final Formula clause = f.or(f1, f2);
        if (this.handler != null) {
            this.proceed = this.handler.createdClause(clause);
        }
        return clause;
    }
    return null;
}

Example 58 with Formula

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

the class TimeoutBDDHandlerTest method testTimeoutHandlerSingleTimeout.

@Test
public void testTimeoutHandlerSingleTimeout() {
    final Formula formula = pg.generate(10);
    final VariableOrderingProvider provider = VariableOrdering.BFS.provider();
    final BDDKernel kernel = new BDDKernel(this.f, provider.getOrder(formula), 100, 100);
    final TimeoutBDDHandler handler = new TimeoutBDDHandler(100L);
    final BDD result = BDDFactory.build(formula, kernel, handler);
    assertThat(handler.aborted).isTrue();
    assertThat(result).isEqualTo(new BDD(BDDKernel.BDD_ABORT, kernel));
}

Example 59 with Formula

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

the class TimeoutBDDHandlerTest method testThatMethodsAreCalled.

@Test
public void testThatMethodsAreCalled() throws ParserException {
    final Formula formula = f.parse("(A => ~B) & ((A & C) | (D & ~C)) & (A | Y | X)");
    final VariableOrderingProvider provider = VariableOrdering.BFS.provider();
    final BDDKernel kernel = new BDDKernel(this.f, provider.getOrder(formula), 100, 100);
    final TimeoutBDDHandler handler = Mockito.mock(TimeoutBDDHandler.class);
    BDDFactory.build(formula, kernel, handler);
    verify(handler, times(1)).started();
    verify(handler, atLeast(1)).newRefAdded();
}

Example 60 with Formula

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

the class TimeoutBDDHandlerTest method testThatNewRefAddedHandledProperly.

@Test
public void testThatNewRefAddedHandledProperly() throws ParserException {
    final Formula formula = f.parse("(A => ~B) & ((A & C) | ~(D & ~C)) & (A | Y | X)");
    final VariableOrderingProvider provider = VariableOrdering.BFS.provider();
    final BDDKernel kernel = new BDDKernel(this.f, provider.getOrder(formula), 100, 100);
    final TimeoutBDDHandler handler = Mockito.mock(TimeoutBDDHandler.class);
    final AtomicInteger count = new AtomicInteger(0);
    when(handler.newRefAdded()).then(invocationOnMock -> count.addAndGet(1) < 5);
    final BDD result = BDDFactory.build(formula, kernel, handler);
    assertThat(result).isEqualTo(new BDD(BDDKernel.BDD_ABORT, kernel));
    verify(handler, times(1)).started();
    verify(handler, times(5)).newRefAdded();
}