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working on mss/mus v2

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-08-29 08:39:31 -07:00
parent 1b9529e1e1
commit c928f776da
3 changed files with 87 additions and 17 deletions
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44
src/opt/maxres.cpp
View file

@ -61,6 +61,7 @@ Notes:
#include "mss.h"
#include "inc_sat_solver.h"
#include "opt_context.h"
#include "pb_decl_plugin.h"
using namespace opt;
@ -85,6 +86,7 @@ private:
rational m_max_upper;
bool m_hill_climb;
bool m_all_cores;
bool m_add_upper_bound_block;
public:
maxres(context& c,
@ -97,7 +99,8 @@ public:
m_trail(m),
m_st(st),
m_hill_climb(true),
m_all_cores(false)
m_all_cores(false),
m_add_upper_bound_block(false)
{
}
@ -281,13 +284,12 @@ public:
*/
lbool mus_mss2_solver() {
m_all_cores = true;
m_add_upper_bound_block = true;
init();
init_local();
sls();
m_all_cores = true;
NOT_IMPLEMENTED_YET();
vector<ptr_vector<expr> > cores;
return l_undef;
lbool is_sat = l_true;
while (m_lower < m_upper && is_sat == l_true) {
TRACE("opt",
@ -318,15 +320,21 @@ public:
break;
}
SASSERT(is_sat == l_true);
// there is some best model,
// TBD: there is some best model,
// retrieve it from the get_cores calls.
// extend it to a maximal assignment
// extracting the mss and mcs.
set_mus(false);
ptr_vector<expr> mss, mcs;
is_sat = m_mss(cores, mss, mcs);
set_mus(true);
if (is_sat != l_true) return is_sat;
//
model_ref mdl;
m_mss.get_model(mdl); // last model is best way to reduce search space.
update_assignment(mdl.get());
is_sat = process_sat(mcs);
}
m_lower = m_upper;
return l_true;
@ -446,14 +454,9 @@ public:
lbool process_sat(ptr_vector<expr> const& corr_set) {
expr_ref fml(m), tmp(m);
TRACE("opt", display_vec(tout << "corr_set: ", corr_set.size(), corr_set.c_ptr()););
if (corr_set.empty()) {
return l_true;
}
remove_core(corr_set);
rational w = split_core(corr_set);
TRACE("opt", display_vec(tout << " corr_set: ", corr_set.size(), corr_set.c_ptr()););
cs_max_resolve(corr_set, w);
cs_max_resolve(corr_set, w);
return l_true;
}
@ -479,6 +482,7 @@ public:
lbool process_unsat(ptr_vector<expr> const& core) {
expr_ref fml(m);
remove_core(core);
SASSERT(!core.empty());
rational w = split_core(core);
TRACE("opt", display_vec(tout << "minimized core: ", core.size(), core.c_ptr()););
max_resolve(core, w);
@ -524,9 +528,8 @@ public:
}
rational split_core(ptr_vector<expr> const& core) {
if (core.empty()) return rational(0);
// find the minimal weight:
SASSERT(!core.empty());
rational w = get_weight(core[0]);
for (unsigned i = 1; i < core.size(); ++i) {
rational w2 = get_weight(core[i]);
@ -602,8 +605,8 @@ public:
// cs is a correction set (a complement of a (maximal) satisfying assignment).
void cs_max_resolve(ptr_vector<expr> const& cs, rational const& w) {
if (cs.empty()) return;
TRACE("opt", display_vec(tout << "correction set: ", cs.size(), cs.c_ptr()););
SASSERT(!cs.empty());
expr_ref fml(m), asum(m);
app_ref cls(m), d(m), dd(m);
m_B.reset();
@ -737,6 +740,17 @@ public:
// verify_assignment();
IF_VERBOSE(1, verbose_stream() <<
"(opt.maxres [" << m_lower << ":" << m_upper << "])\n";);
if (m_add_upper_bound_block) {
pb_util u(m);
expr_ref_vector nsoft(m);
expr_ref fml(m);
for (unsigned i = 0; i < m_soft.size(); ++i) {
nsoft.push_back(m.mk_not(m_soft[i].get()));
}
fml = u.mk_lt(nsoft.size(), m_weights.c_ptr(), nsoft.c_ptr(), m_upper);
s().assert_expr(fml);
}
}
void remove_soft(ptr_vector<expr> const& core, expr_ref_vector& asms) {

50
src/opt/mus.cpp
View file

@ -22,7 +22,6 @@ Notes:
#include "smt_literal.h"
#include "mus.h"
#include "ast_pp.h"
#include "model_smt2_pp.h"
using namespace opt;
@ -34,9 +33,13 @@ struct mus::imp {
expr_ref_vector m_cls2expr;
obj_map<expr, unsigned> m_expr2cls;
volatile bool m_cancel;
model_ref m_model;
expr_ref_vector m_soft;
vector<rational> m_weights;
rational m_weight;
imp(solver& s, ast_manager& m):
m_s(s), m(m), m_cls2expr(m), m_cancel(false)
m_s(s), m(m), m_cls2expr(m), m_cancel(false), m_soft(m)
{}
void reset() {
@ -100,6 +103,7 @@ struct mus::imp {
case l_true:
assumptions.push_back(cls);
mus.push_back(cls_id);
update_model();
break;
default:
core_exprs.reset();
@ -145,6 +149,40 @@ struct mus::imp {
out << "\n";
}
void set_soft(unsigned sz, expr* const* soft, rational const* weights) {
m_model.reset();
m_weight.reset();
m_soft.append(sz, soft);
m_weights.append(sz, weights);
for (unsigned i = 0; i < sz; ++i) {
m_weight += weights[i];
}
}
void update_model() {
if (m_soft.empty()) return;
model_ref mdl;
expr_ref tmp(m);
m_s.get_model(mdl);
rational w;
for (unsigned i = 0; i < m_soft.size(); ++i) {
mdl->eval(m_soft[i].get(), tmp);
if (!m.is_true(tmp)) {
w += m_weights[i];
}
}
if (w < m_weight || !m_model.get()) {
m_model = mdl;
m_weight = w;
}
}
rational get_best_model(model_ref& mdl) {
mdl = m_model;
return m_weight;
}
};
mus::mus(solver& s, ast_manager& m) {
@ -170,3 +208,11 @@ void mus::set_cancel(bool f) {
void mus::reset() {
m_imp->reset();
}
void mus::set_soft(unsigned sz, expr* const* soft, rational const* weights) {
m_imp->set_soft(sz, soft, weights);
}
rational mus::get_best_model(model_ref& mdl) {
return m_imp->get_best_model(mdl);
}

10
src/opt/mus.h
View file

@ -40,6 +40,16 @@ namespace opt {
void reset();
void set_cancel(bool f);
/**
Instrument MUS extraction to also provide the minimal
penalty model, if any is found.
The minimal penalty model has the least weight for the
supplied soft constraints.
*/
void set_soft(unsigned sz, expr* const* soft, rational const* weights);
rational get_best_model(model_ref& mdl);
};
};