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redo purification

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-10-29 11:06:31 -07:00
parent da0e140e1c
commit 2e684d58d2
5 changed files with 68 additions and 88 deletions
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63
src/sat/smt/q_mbi.cpp
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@ -36,8 +36,7 @@ namespace q {
m_qs(s),
m(s.get_manager()),
m_model_fixer(ctx, m_qs),
m_fresh_trail(m)
{
m_fresh_trail(m) {
auto* ap = alloc(mbp::arith_project_plugin, m);
ap->set_check_purified(false);
ap->set_apply_projection(true);
@ -120,9 +119,9 @@ namespace q {
if (is_exists(q))
qlit.neg();
unsigned i = 0;
{
if (!qb->var_args.empty()) {
::solver::scoped_push _sp(*m_solver);
restrict_domains(*mdl0, *qb);
add_domain_eqs(*mdl0, *qb);
for (; i < m_max_cex && l_true == m_solver->check_sat(0, nullptr); ++i) {
m_solver->get_model(mdl1);
proj = solver_project(*mdl1, *qb);
@ -133,7 +132,7 @@ namespace q {
}
}
if (i == 0) {
qb->domain_eqs.reset();
add_domain_bounds(*mdl0, *qb);
proj = solver_project(*mdl0, *qb);
if (!proj)
return l_undef;
@ -212,14 +211,17 @@ namespace q {
expr_ref_vector fmls(qb.vbody);
app_ref_vector vars(qb.vars);
fmls.append(qb.domain_eqs);
eliminate_nested_vars(fmls, qb);
mbp::project_plugin proj(m);
proj.purify(m_model_fixer, *m_model, vars, fmls);
proj.extract_literals(*m_model, vars, fmls);
for (unsigned i = 0; i < vars.size(); ++i) {
app* v = vars.get(i);
auto* p = get_plugin(v);
if (p)
(*p)(*m_model, vars, fmls);
}
#if 0
// should be redundant
expr_safe_replace esubst(m);
for (app* v : qb.vars) {
expr_ref val = assign_value(*m_model, v);
@ -228,6 +230,7 @@ namespace q {
esubst.insert(v, val);
}
esubst(fmls);
#endif
return mk_and(fmls);
}
@ -238,7 +241,7 @@ namespace q {
* Add also disjunctions to the quantifier "domain_eqs", to track the constraints
* added to the solver.
*/
void mbqi::restrict_domains(model& mdl, q_body& qb) {
void mbqi::add_domain_eqs(model& mdl, q_body& qb) {
qb.domain_eqs.reset();
var_subst subst(m);
for (auto p : qb.var_args) {
@ -256,6 +259,43 @@ namespace q {
}
}
/*
* Add bounds to sub-terms under uninterpreted functions for projection.
*/
void mbqi::add_domain_bounds(model& mdl, q_body& qb) {
qb.domain_eqs.reset();
for (app* v : qb.vars)
m_model->register_decl(v->get_decl(), mdl(v));
if (qb.var_args.empty())
return;
var_subst subst(m);
for (auto p : qb.var_args) {
expr_ref _term = subst(p.first, qb.vars);
app_ref term(to_app(_term), m);
expr_ref value = (*m_model)(term->get_arg(p.second));
m_model_fixer.invert_arg(term, p.second, value, qb.domain_eqs);
}
}
/*
* Remove occurrences of free functions that contain variables.
*/
void mbqi::eliminate_nested_vars(expr_ref_vector& fmls, q_body& qb) {
if (qb.var_args.empty())
return;
expr_safe_replace rep(m);
var_subst subst(m);
for (auto p : qb.var_args) {
expr_ref _term = subst(p.first, qb.vars);
app_ref term(to_app(_term), m);
expr_ref value = (*m_model)(term);
expr* s = m_model_fixer.invert_app(term, value);
rep.insert(term, s);
}
rep(fmls);
}
/*
* Add domain restrictions for every non-ground arguments to uninterpreted functions.
*/
@ -265,10 +305,11 @@ namespace q {
if (is_ground(s))
continue;
if (is_uninterp(s) && to_app(s)->get_num_args() > 0) {
app* a = to_app(s);
for (unsigned i = 0; i < a->get_num_args(); ++i) {
if (is_ground(a->get_arg(i)))
qb.var_args.push_back(std::make_pair(a, i));
unsigned i = 0;
for (expr* arg : *to_app(s)) {
if (!is_ground(arg) && !is_uninterp(arg))
qb.var_args.push_back(std::make_pair(to_app(s), i));
++i;
}
}
}