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Fix bugs in iuc generation

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This commit is contained in:
Arie Gurfinkel 2018-06-20 23:04:44 -04:00
parent 4ed6783aff
commit ac23002dce
2 changed files with 43 additions and 42 deletions
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2
src/muz/spacer/spacer_iuc_proof.h
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@ -33,7 +33,7 @@ public:
bool is_h_marked(proof* p) {return m_h_mark.is_marked(p);}
bool is_b_pure (proof *p) {
return !is_h_marked (p) && is_core_pure(m.get_fact (p));
return !is_h_marked(p) && !this->is_a_marked(p) && is_core_pure(m.get_fact(p));
}
void display_dot(std::ostream &out);

83
src/muz/spacer/spacer_unsat_core_plugin.cpp
View file

@ -34,15 +34,15 @@ Revision History:
namespace spacer {
unsat_core_plugin::unsat_core_plugin(unsat_core_learner& learner):
unsat_core_plugin::unsat_core_plugin(unsat_core_learner& learner):
m(learner.m), m_learner(learner) {};
void unsat_core_plugin_lemma::compute_partial_core(proof* step) {
SASSERT(m_learner.m_pr.is_a_marked(step));
SASSERT(m_learner.m_pr.is_b_marked(step));
for (proof* premise : m.get_parents(step)) {
if (m_learner.is_b_open (premise)) {
// by IH, premises that are AB marked are already closed
SASSERT(!m_learner.m_pr.is_a_marked(premise));
@ -51,18 +51,18 @@ namespace spacer {
}
m_learner.set_closed(step, true);
}
void unsat_core_plugin_lemma::add_lowest_split_to_core(proof* step) const
{
SASSERT(m_learner.is_b_open(step));
ptr_buffer<proof> todo;
todo.push_back(step);
while (!todo.empty()) {
proof* pf = todo.back();
todo.pop_back();
// if current step hasn't been processed,
if (!m_learner.is_closed(pf)) {
m_learner.set_closed(pf, true);
@ -71,7 +71,7 @@ namespace spacer {
// so if it is also a-marked, it must be closed
SASSERT(m_learner.m_pr.is_b_marked(pf));
SASSERT(!m_learner.m_pr.is_a_marked(pf));
// the current step needs to be interpolated:
expr* fact = m.get_fact(pf);
// if we trust the current step and we are able to use it
@ -82,11 +82,11 @@ namespace spacer {
}
// otherwise recurse on premises
else {
for (proof* premise : m.get_parents(pf))
if (m_learner.is_b_open(premise))
for (proof* premise : m.get_parents(pf))
if (m_learner.is_b_open(premise))
todo.push_back(premise);
}
}
}
}
@ -101,15 +101,15 @@ namespace spacer {
func_decl* d = step->get_decl();
symbol sym;
if (!m_learner.is_closed(step) && // if step is not already interpolated
is_farkas_lemma(m, step)) {
// weaker check: d->get_num_parameters() >= m.get_num_parents(step) + 2
is_farkas_lemma(m, step)) {
// weaker check : d->get_num_parameters() >= m.get_num_parents(step) + 2
SASSERT(d->get_num_parameters() == m.get_num_parents(step) + 2);
SASSERT(m.has_fact(step));
coeff_lits_t coeff_lits;
expr_ref_vector pinned(m);
/* The farkas lemma represents a subproof starting from premise(-set)s A, BNP and BP(ure) and
* ending in a disjunction D. We need to compute the contribution of BP, i.e. a formula, which
* is entailed by BP and together with A and BNP entails D.
@ -134,34 +134,35 @@ namespace spacer {
* as workaround we take the absolute value of the provided coefficients.
*/
parameter const* params = d->get_parameters() + 2; // point to the first Farkas coefficient
STRACE("spacer.farkas",
verbose_stream() << "Farkas input: "<< "\n";
TRACE("spacer.farkas",
tout << "Farkas input: "<< "\n";
for (unsigned i = 0; i < m.get_num_parents(step); ++i) {
proof * prem = m.get_parent(step, i);
rational coef = params[i].get_rational();
proof * prem = m.get_parent(step, i);
rational coef = params[i].get_rational();
bool b_pure = m_learner.m_pr.is_b_pure (prem);
verbose_stream() << (b_pure?"B":"A") << " " << coef << " " << mk_pp(m.get_fact(prem), m) << "\n";
tout << (b_pure?"B":"A") << " " << coef << " " << mk_pp(m.get_fact(prem), m) << "\n";
}
);
bool can_be_closed = true;
for (unsigned i = 0; i < m.get_num_parents(step); ++i) {
proof * premise = m.get_parent(step, i);
if (m_learner.is_b_open (premise)) {
SASSERT(!m_learner.m_pr.is_a_marked(premise));
if (m_learner.m_pr.is_b_pure (step)) {
if (m_learner.m_pr.is_b_pure (premise)) {
if (!m_use_constant_from_a) {
rational coefficient = params[i].get_rational();
coeff_lits.push_back(std::make_pair(abs(coefficient), (app*)m.get_fact(premise)));
}
}
else {
// -- mixed premise, won't be able to close this proof step
can_be_closed = false;
if (m_use_constant_from_a) {
rational coefficient = params[i].get_rational();
coeff_lits.push_back(std::make_pair(abs(coefficient), (app*)m.get_fact(premise)));
@ -175,10 +176,10 @@ namespace spacer {
}
}
}
if (m_use_constant_from_a) {
params += m.get_num_parents(step); // point to the first Farkas coefficient, which corresponds to a formula in the conclusion
// the conclusion can either be a single formula or a disjunction of several formulas, we have to deal with both situations
if (m.get_num_parents(step) + 2 < d->get_num_parameters()) {
unsigned num_args = 1;
@ -190,7 +191,7 @@ namespace spacer {
args = _or->get_args();
}
SASSERT(m.get_num_parents(step) + 2 + num_args == d->get_num_parameters());
bool_rewriter brw(m);
for (unsigned i = 0; i < num_args; ++i) {
expr* premise = args[i];
@ -205,11 +206,11 @@ namespace spacer {
}
// only if all b-premises can be used directly, add the farkas core and close the step
// AG: this decision needs to be re-evaluated. If the proof cannot be closed, literals above
// AG: it will go into the core. However, it does not mean that this literal should/could not be added.
if (can_be_closed) {
m_learner.set_closed(step, true);
expr_ref res = compute_linear_combination(coeff_lits);
m_learner.add_lemma_to_core(res);
}
}
@ -253,7 +254,7 @@ namespace spacer {
verbose_stream() << "Farkas input: "<< "\n";
for (unsigned i = 0; i < m.get_num_parents(step); ++i) {
proof * prem = m.get_parent(step, i);
rational coef = params[i].get_rational();
rational coef = params[i].get_rational();
bool b_pure = m_learner.m_pr.is_b_pure (prem);
verbose_stream() << (b_pure?"B":"A") << " " << coef << " " << mk_pp(m.get_fact(prem), m_learner.m) << "\n";
}
@ -340,7 +341,7 @@ namespace spacer {
// 4. extract linear combinations from matrix and add result to core
for (unsigned k = 0; k < i; ++k)// i points to the row after the last row which is non-zero
{
coeff_lits_t coeff_lits;
coeff_lits_t coeff_lits;
for (unsigned l = 0; l < matrix.num_cols(); ++l) {
if (!matrix.get(k,l).is_zero()) {
coeff_lits.push_back(std::make_pair(matrix.get(k, l), ordered_basis[l]));
@ -354,14 +355,14 @@ namespace spacer {
}
expr_ref unsat_core_plugin_farkas_lemma_optimized::compute_linear_combination(const coeff_lits_t& coeff_lits) {
expr_ref unsat_core_plugin_farkas_lemma_optimized::compute_linear_combination(const coeff_lits_t& coeff_lits) {
smt::farkas_util util(m);
for (auto const & p : coeff_lits) {
util.add(p.first, p.second);
}
expr_ref negated_linear_combination = util.get();
SASSERT(m.is_not(negated_linear_combination));
return expr_ref(mk_not(m, negated_linear_combination), m);
return expr_ref(mk_not(m, negated_linear_combination), m);
//TODO: rewrite the get-method to return nonnegated stuff?
}
@ -449,7 +450,7 @@ namespace spacer {
for (unsigned j = 0; j < matrix.num_cols(); ++j) {
SASSERT(matrix.get(i, j).is_int());
app_ref a_ij(util.mk_numeral(matrix.get(i,j), true), m);
app_ref sum(util.mk_int(0), m);
for (unsigned k = 0; k < n; ++k) {
sum = util.mk_add(sum, util.mk_mul(coeffs[i][k].get(), bounded_vectors[j][k].get()));
@ -458,7 +459,7 @@ namespace spacer {
s->assert_expr(eq);
}
}
// check result
lbool res = s->check_sat(0, nullptr);
@ -682,7 +683,7 @@ namespace spacer {
void unsat_core_plugin_min_cut::finalize() {
unsigned_vector cut_nodes;
m_min_cut.compute_min_cut(cut_nodes);
for (unsigned cut_node : cut_nodes) {
m_learner.add_lemma_to_core(m_node_to_formula[cut_node]);
}