Examples with UNSATCore org.logicng.explanations.UNSATCore used on opensource projects

Example 1 with UNSATCore

use of org.logicng.explanations.UNSATCore in project LogicNG by logic-ng.

the class UnsatCoreFunction method apply.

@Override
public UNSATCore<Proposition> apply(final MiniSat solver, final Consumer<Tristate> resultSetter) {
    if (!solver.getConfig().proofGeneration()) {
        throw new IllegalStateException("Cannot generate an unsat core if proof generation is not turned on");
    }
    if (solver.getResult() == TRUE) {
        throw new IllegalStateException("An unsat core can only be generated if the formula is solved and is UNSAT");
    }
    if (solver.getResult() == Tristate.UNDEF) {
        throw new IllegalStateException("Cannot generate an unsat core before the formula was solved.");
    }
    if (solver.underlyingSolver() instanceof MiniCard) {
        throw new IllegalStateException("Cannot compute an unsat core with MiniCard.");
    }
    if (solver.underlyingSolver() instanceof GlucoseSyrup && solver.getConfig().incremental()) {
        throw new IllegalStateException("Cannot compute an unsat core with Glucose in incremental mode.");
    }
    if (solver.isLastComputationWithAssumptions()) {
        throw new IllegalStateException("Cannot compute an unsat core for a computation with assumptions.");
    }
    final DRUPTrim trimmer = new DRUPTrim();
    final Map<Formula, Proposition> clause2proposition = new HashMap<>();
    final LNGVector<LNGIntVector> clauses = new LNGVector<>(solver.underlyingSolver().pgOriginalClauses().size());
    for (final MiniSatStyleSolver.ProofInformation pi : solver.underlyingSolver().pgOriginalClauses()) {
        clauses.push(pi.clause());
        final Formula clause = getFormulaForVector(solver, pi.clause());
        Proposition proposition = pi.proposition();
        if (proposition == null) {
            proposition = new StandardProposition(clause);
        }
        clause2proposition.put(clause, proposition);
    }
    if (containsEmptyClause(clauses)) {
        final Proposition emptyClause = clause2proposition.get(solver.factory().falsum());
        return new UNSATCore<>(Collections.singletonList(emptyClause), true);
    }
    final DRUPTrim.DRUPResult result = trimmer.compute(clauses, solver.underlyingSolver().pgProof());
    if (result.trivialUnsat()) {
        return handleTrivialCase(solver);
    }
    final LinkedHashSet<Proposition> propositions = new LinkedHashSet<>();
    for (final LNGIntVector vector : result.unsatCore()) {
        propositions.add(clause2proposition.get(getFormulaForVector(solver, vector)));
    }
    return new UNSATCore<>(new ArrayList<>(propositions), false);
}

Example 2 with UNSATCore

use of org.logicng.explanations.UNSATCore in project LogicNG by logic-ng.

the class DeletionBasedMUS method computeMUS.

@Override
public <T extends Proposition> UNSATCore<T> computeMUS(final List<T> propositions, final FormulaFactory f, final MUSConfig config) {
    start(config.handler);
    final List<T> mus = new ArrayList<>(propositions.size());
    final List<SolverState> solverStates = new ArrayList<>(propositions.size());
    final MiniSat solver = MiniSat.miniSat(f);
    for (final Proposition proposition : propositions) {
        solverStates.add(solver.saveState());
        solver.add(proposition);
    }
    boolean sat = solver.sat() == Tristate.TRUE;
    if (aborted(config.handler)) {
        return null;
    }
    if (sat) {
        throw new IllegalArgumentException("Cannot compute a MUS for a satisfiable formula set.");
    }
    for (int i = solverStates.size() - 1; i >= 0; i--) {
        solver.loadState(solverStates.get(i));
        for (final Proposition prop : mus) {
            solver.add(prop);
        }
        sat = solver.sat(config.handler) == Tristate.TRUE;
        if (aborted(config.handler)) {
            return null;
        }
        if (sat) {
            mus.add(propositions.get(i));
        }
    }
    return new UNSATCore<>(mus, true);
}

Example 3 with UNSATCore

use of org.logicng.explanations.UNSATCore in project LogicNG by logic-ng.

the class PlainInsertionBasedMUS method computeMUS.

@Override
public <T extends Proposition> UNSATCore<T> computeMUS(final List<T> propositions, final FormulaFactory f, final MUSConfig config) {
    start(config.handler);
    final List<T> currentFormula = new ArrayList<>(propositions.size());
    currentFormula.addAll(propositions);
    final List<T> mus = new ArrayList<>(propositions.size());
    final MiniSat solver = MiniSat.miniSat(f);
    while (!currentFormula.isEmpty()) {
        final List<T> currentSubset = new ArrayList<>(propositions.size());
        T transitionProposition = null;
        solver.reset();
        for (final Proposition p : mus) {
            solver.add(p);
        }
        int count = currentFormula.size();
        while (shouldProceed(solver, config.handler)) {
            if (count == 0) {
                throw new IllegalArgumentException("Cannot compute a MUS for a satisfiable formula set.");
            }
            final T removeProposition = currentFormula.get(--count);
            currentSubset.add(removeProposition);
            transitionProposition = removeProposition;
            solver.add(removeProposition);
        }
        if (aborted(config.handler)) {
            return null;
        }
        currentFormula.clear();
        currentFormula.addAll(currentSubset);
        if (transitionProposition != null) {
            currentFormula.remove(transitionProposition);
            mus.add(transitionProposition);
        }
    }
    return new UNSATCore<>(mus, true);
}

Example 4 with UNSATCore

use of org.logicng.explanations.UNSATCore in project LogicNG by logic-ng.

the class UnsatCoreFunction method handleTrivialCase.

private UNSATCore<Proposition> handleTrivialCase(final MiniSat solver) {
    final LNGVector<MiniSatStyleSolver.ProofInformation> clauses = solver.underlyingSolver().pgOriginalClauses();
    for (int i = 0; i < clauses.size(); i++) {
        for (int j = i + 1; j < clauses.size(); j++) {
            if (clauses.get(i).clause().size() == 1 && clauses.get(j).clause().size() == 1 && clauses.get(i).clause().get(0) + clauses.get(j).clause().get(0) == 0) {
                final LinkedHashSet<Proposition> propositions = new LinkedHashSet<>();
                final Proposition pi = clauses.get(i).proposition();
                final Proposition pj = clauses.get(j).proposition();
                propositions.add(pi != null ? pi : new StandardProposition(getFormulaForVector(solver, clauses.get(i).clause())));
                propositions.add(pj != null ? pj : new StandardProposition(getFormulaForVector(solver, clauses.get(j).clause())));
                return new UNSATCore<>(new ArrayList<>(propositions), false);
            }
        }
    }
    throw new IllegalStateException("Should be a trivial unsat core, but did not found one.");
}