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

Example 91 with Literal

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

the class SATTest method testUPZeroLiteralsUNSAT.

@Test
public void testUPZeroLiteralsUNSAT() throws ParserException {
    final Formula formula = this.parser.parse("a & (a => b) & (b => c) & (c => ~a)");
    for (final SATSolver solver : this.solvers) {
        solver.reset();
        solver.add(formula);
        solver.sat();
        final SortedSet<Literal> upLiterals = solver.execute(UpZeroLiteralsFunction.get());
        assertThat(upLiterals).isNull();
    }
}

Example 92 with Literal

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

the class SATTest method testHighestLexicographicalAssignment.

/**
 * Tests if the given satisfying assignment is the highest assignment in the lexicographical order based on the given
 * literals order.
 * @param solver     the solver with the loaded formulas
 * @param assignment the satisfying assignment
 * @param order      the literals order
 */
private void testHighestLexicographicalAssignment(final SATSolver solver, final Assignment assignment, final List<? extends Literal> order) {
    final SortedSet<Literal> literals = assignment.literals();
    final List<Literal> orderSublist = new ArrayList<>();
    for (final Literal lit : order) {
        final boolean containsLit = literals.contains(lit);
        if (!containsLit) {
            final SortedSet<Literal> orderSubsetWithFlip = new TreeSet<>(orderSublist);
            orderSubsetWithFlip.remove(lit.negate());
            orderSubsetWithFlip.add(lit);
            assertThat(solver.sat(orderSubsetWithFlip)).isEqualTo(Tristate.FALSE);
        }
        orderSublist.add(containsLit ? lit : lit.negate());
    }
}

Example 93 with Literal

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

the class FormulaRandomizerTest method testLiteral.

@Test
public void testLiteral() {
    final FormulaRandomizer random = new FormulaRandomizer(this.f, FormulaRandomizerConfig.builder().weightPositiveLiteral(40).weightNegativeLiteral(60).seed(42).build());
    int numPos = 0;
    for (int i = 0; i < 100; i++) {
        final Literal literal = random.literal();
        if (literal.phase()) {
            numPos++;
        }
    }
    assertThat(numPos).isStrictlyBetween(30, 50);
}

Example 94 with Literal

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

the class CCModularTotalizer method finalAdder.

private void finalAdder(final int mod, final LNGVector<Literal> upper, final LNGVector<Literal> lupper, final LNGVector<Literal> rupper, final Variable carry) {
    for (int i = 0; i <= lupper.size(); i++) {
        for (int j = 0; j <= rupper.size(); j++) {
            Literal a = this.varError;
            Literal b = this.varError;
            Literal c = this.varError;
            Literal d = this.varError;
            int closeMod = this.currentCardinalityRhs / mod;
            if (this.currentCardinalityRhs % mod != 0) {
                closeMod++;
            }
            if (mod * (i + j) > closeMod * mod) {
                continue;
            }
            if (i != 0) {
                a = lupper.get(i - 1);
            }
            if (j != 0) {
                b = rupper.get(j - 1);
            }
            if (i + j != 0 && i + j - 1 < upper.size()) {
                c = upper.get(i + j - 1);
            }
            if (i + j < upper.size()) {
                d = upper.get(i + j);
            }
            if (c != this.varUndef && c != this.varError) {
                final LNGVector<Literal> clause = new LNGVector<>();
                if (a != this.varUndef && a != this.varError) {
                    clause.push(a.negate());
                }
                if (b != this.varUndef && b != this.varError) {
                    clause.push(b.negate());
                }
                clause.push(c);
                if (clause.size() > 1) {
                    this.result.addClause(clause);
                }
            }
            final LNGVector<Literal> clause = new LNGVector<>();
            clause.push(carry.negate());
            if (a != this.varUndef && a != this.varError) {
                clause.push(a.negate());
            }
            if (b != this.varUndef && b != this.varError) {
                clause.push(b.negate());
            }
            if (d != this.varError && d != this.varUndef) {
                clause.push(d);
            }
            if (clause.size() > 1) {
                this.result.addClause(clause);
            }
        }
    }
}

Example 95 with Literal

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

the class CCSorting method recursiveMerger.

private void recursiveMerger(final int c, final LNGVector<Literal> inputA, final int a, final LNGVector<Literal> inputB, final int b, final EncodingResult formula, final LNGVector<Literal> output, final ImplicationDirection direction) {
    assert inputA.size() > 0;
    assert inputB.size() > 0;
    assert c > 0;
    output.clear();
    int a2 = a;
    int b2 = b;
    if (a2 > c) {
        a2 = c;
    }
    if (b2 > c) {
        b2 = c;
    }
    if (c == 1) {
        final Variable y = formula.newVariable();
        comparator(inputA.get(0), inputB.get(0), y, formula, direction);
        output.push(y);
        return;
    }
    if (a2 == 1 && b2 == 1) {
        assert c == 2;
        final Variable y1 = formula.newVariable();
        final Variable y2 = formula.newVariable();
        comparator(inputA.get(0), inputB.get(0), y1, y2, formula, direction);
        output.push(y1);
        output.push(y2);
        return;
    }
    final LNGVector<Literal> oddMerge = new LNGVector<>();
    final LNGVector<Literal> evenMerge = new LNGVector<>();
    final LNGVector<Literal> tmpLitsOddA = new LNGVector<>();
    final LNGVector<Literal> tmpLitsOddB = new LNGVector<>();
    final LNGVector<Literal> tmpLitsEvenA = new LNGVector<>();
    final LNGVector<Literal> tmpLitsEvenB = new LNGVector<>();
    for (int i = 0; i < a2; i = i + 2) {
        tmpLitsOddA.push(inputA.get(i));
    }
    for (int i = 0; i < b2; i = i + 2) {
        tmpLitsOddB.push(inputB.get(i));
    }
    for (int i = 1; i < a2; i = i + 2) {
        tmpLitsEvenA.push(inputA.get(i));
    }
    for (int i = 1; i < b2; i = i + 2) {
        tmpLitsEvenB.push(inputB.get(i));
    }
    merge(c / 2 + 1, tmpLitsOddA, tmpLitsOddB, formula, oddMerge, direction);
    merge(c / 2, tmpLitsEvenA, tmpLitsEvenB, formula, evenMerge, direction);
    assert oddMerge.size() > 0;
    output.push(oddMerge.get(0));
    int i = 1;
    int j = 0;
    while (true) {
        if (i < oddMerge.size() && j < evenMerge.size()) {
            if (output.size() + 2 <= c) {
                final Variable z0 = formula.newVariable();
                final Variable z1 = formula.newVariable();
                comparator(oddMerge.get(i), evenMerge.get(j), z0, z1, formula, direction);
                output.push(z0);
                output.push(z1);
                if (output.size() == c) {
                    break;
                }
            } else if (output.size() + 1 == c) {
                final Variable z0 = formula.newVariable();
                comparator(oddMerge.get(i), evenMerge.get(j), z0, formula, direction);
                output.push(z0);
                break;
            }
        } else if (i >= oddMerge.size() && j >= evenMerge.size()) {
            break;
        } else if (i >= oddMerge.size()) {
            assert j == evenMerge.size() - 1;
            output.push(evenMerge.back());
            break;
        } else {
            assert i == oddMerge.size() - 1;
            output.push(oddMerge.back());
            break;
        }
        i++;
        j++;
    }
    assert output.size() == a2 + b2 || output.size() == c;
}