mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-10 19:27:06 +00:00
Code Activity

add facility to dispense with cancellation (not activated at this point). Address by expanding recurisve function definitions that are not tautologies if the current model does not validate

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-04-07 21:22:38 -07:00
parent 0c4b792dac
commit ec29a03c8f
8 changed files with 62 additions and 28 deletions

3
src/sat/sat_simplifier.cpp
View file

@ -154,6 +154,8 @@ namespace sat {
if (!m_subsumption && !m_elim_blocked_clauses && !m_resolution)
return;
// solver::scoped_disable_checkpoint _scoped_disable_checkpoint(s);
initialize();
CASSERT("sat_solver", s.check_invariant());
@ -167,7 +169,6 @@ namespace sat {
CASSERT("sat_solver", s.check_invariant());
m_need_cleanup = false;
m_use_list.init(s.num_vars());
init_visited();
m_learned_in_use_lists = false;
if (learned) {
register_clauses(s.m_learned);

1
src/sat/sat_solver.cpp
View file

@ -33,6 +33,7 @@ namespace sat {
solver::solver(params_ref const & p, reslimit& l, extension * ext):
m_rlimit(l),
m_checkpoint_enabled(true),
m_config(p),
m_ext(ext),
m_par(0),

12
src/sat/sat_solver.h
View file

@ -72,6 +72,7 @@ namespace sat {
struct abort_solver {};
protected:
reslimit& m_rlimit;
bool m_checkpoint_enabled;
config m_config;
stats m_stats;
extension * m_ext;
@ -214,6 +215,16 @@ namespace sat {
}
}
};
class scoped_disable_checkpoint {
solver& s;
public:
scoped_disable_checkpoint(solver& s): s(s) {
s.m_checkpoint_enabled = false;
}
~scoped_disable_checkpoint() {
s.m_checkpoint_enabled = true;
}
};
unsigned select_watch_lit(clause const & cls, unsigned starting_at) const;
unsigned select_learned_watch_lit(clause const & cls) const;
bool simplify_clause(unsigned & num_lits, literal * lits) const;
@ -257,6 +268,7 @@ namespace sat {
lbool status(clause const & c) const;
clause_offset get_offset(clause const & c) const { return m_cls_allocator.get_offset(&c); }
void checkpoint() {
if (!m_checkpoint_enabled) return;
if (!m_rlimit.inc()) {
m_mc.reset();
m_model_is_current = false;

3
src/smt/smt_context_inv.cpp
View file

@ -433,6 +433,9 @@ namespace smt {
if (!is_ground(n)) {
continue;
}
if (is_quantifier(n) && m.is_rec_fun_def(to_quantifier(n))) {
continue;
}
switch (get_assignment(*it)) {
case l_undef:
break;

62
src/smt/smt_model_checker.cpp
View file

@ -316,7 +316,7 @@ namespace smt {
return false;
}
bool model_checker::check_rec_fun(quantifier* q) {
bool model_checker::check_rec_fun(quantifier* q, bool strict_rec_fun) {
TRACE("model_checker", tout << mk_pp(q, m) << "\n";);
SASSERT(q->get_num_patterns() == 2); // first pattern is the function, second is the body.
expr* fn = to_app(q->get_pattern(0))->get_arg(0);
@ -340,7 +340,7 @@ namespace smt {
}
sub(q->get_expr(), num_decls, args.c_ptr(), tmp);
m_curr_model->eval(tmp, result, true);
if (m.is_false(result)) {
if (strict_rec_fun ? !m.is_true(result) : m.is_false(result)) {
add_instance(q, args, 0);
return false;
}
@ -365,10 +365,10 @@ namespace smt {
bool model_checker::check(proto_model * md, obj_map<enode, app *> const & root2value) {
SASSERT(md != 0);
m_root2value = &root2value;
ptr_vector<quantifier>::const_iterator it = m_qm->begin_quantifiers();
ptr_vector<quantifier>::const_iterator end = m_qm->end_quantifiers();
if (it == end)
if (m_qm->num_quantifiers() == 0)
return true;
if (m_iteration_idx >= m_params.m_mbqi_max_iterations) {
@ -393,6 +393,36 @@ namespace smt {
bool found_relevant = false;
unsigned num_failures = 0;
check_quantifiers(false, found_relevant, num_failures);
if (found_relevant)
m_iteration_idx++;
TRACE("model_checker", tout << "model after check:\n"; model_pp(tout, *md););
TRACE("model_checker", tout << "model checker result: " << (num_failures == 0) << "\n";);
m_max_cexs += m_params.m_mbqi_max_cexs;
if (num_failures == 0 && !m_context->validate_model()) {
num_failures = 1;
// this time force expanding recursive function definitions
// that are not forced true in the current model.
check_quantifiers(true, found_relevant, num_failures);
}
if (num_failures == 0)
m_curr_model->cleanup();
if (m_params.m_mbqi_trace) {
if (num_failures == 0)
verbose_stream() << "(smt.mbqi :succeeded true)\n";
else
verbose_stream() << "(smt.mbqi :num-failures " << num_failures << ")\n";
}
return num_failures == 0;
}
void model_checker::check_quantifiers(bool strict_rec_fun, bool& found_relevant, unsigned& num_failures) {
ptr_vector<quantifier>::const_iterator it = m_qm->begin_quantifiers();
ptr_vector<quantifier>::const_iterator end = m_qm->end_quantifiers();
for (; it != end; ++it) {
quantifier * q = *it;
if(!m_qm->mbqi_enabled(q)) continue;
@ -406,7 +436,7 @@ namespace smt {
}
found_relevant = true;
if (m.is_rec_fun_def(q)) {
if (!check_rec_fun(q)) {
if (!check_rec_fun(q, strict_rec_fun)) {
TRACE("model_checker", tout << "checking recursive function failed\n";);
num_failures++;
}
@ -420,26 +450,6 @@ namespace smt {
}
}
}
if (found_relevant)
m_iteration_idx++;
TRACE("model_checker", tout << "model after check:\n"; model_pp(tout, *md););
TRACE("model_checker", tout << "model checker result: " << (num_failures == 0) << "\n";);
m_max_cexs += m_params.m_mbqi_max_cexs;
if (num_failures == 0 && !m_context->validate_model()) {
num_failures = 1;
}
if (num_failures == 0)
m_curr_model->cleanup();
if (m_params.m_mbqi_trace) {
if (num_failures == 0)
verbose_stream() << "(smt.mbqi :succeeded true)\n";
else
verbose_stream() << "(smt.mbqi :num-failures " << num_failures << ")\n";
}
return num_failures == 0;
}
void model_checker::init_search_eh() {

3
src/smt/smt_model_checker.h
View file

@ -59,7 +59,8 @@ namespace smt {
void assert_neg_q_m(quantifier * q, expr_ref_vector & sks);
bool add_blocking_clause(model * cex, expr_ref_vector & sks);
bool check(quantifier * q);
bool check_rec_fun(quantifier* q);
bool check_rec_fun(quantifier* q, bool strict_rec_fun);
void check_quantifiers(bool strict_rec_fun, bool& found_relevant, unsigned& num_failures);
struct instance {
quantifier * m_q;

4
src/smt/smt_quantifier.cpp
View file

@ -397,6 +397,10 @@ namespace smt {
return m_imp->m_quantifiers.end();
}
unsigned quantifier_manager::num_quantifiers() const {
return m_imp->m_quantifiers.size();
}
// The default plugin uses E-matching, MBQI and quick-checker
class default_qm_plugin : public quantifier_manager_plugin {
quantifier_manager * m_qm;

2
src/smt/smt_quantifier.h
View file

@ -91,6 +91,8 @@ namespace smt {
ptr_vector<quantifier>::const_iterator begin_quantifiers() const;
ptr_vector<quantifier>::const_iterator end_quantifiers() const;
unsigned num_quantifiers() const;
};
class quantifier_manager_plugin {