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testing maxres with sat core

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-08-02 12:27:57 -07:00
parent b928734348
commit 8814ba0629
12 changed files with 187 additions and 298 deletions

View file

@ -27,16 +27,9 @@ using namespace opt;
class maxres : public maxsmt_solver_base {
struct info {
app* m_cls;
rational m_weight;
info(app* cls, rational const& w):
m_cls(cls), m_weight(w) {}
info(): m_cls(0) {}
};
expr_ref_vector m_B;
expr_ref_vector m_asms;
obj_map<expr, info> m_asm2info;
obj_map<expr, rational> m_asm2weight;
ptr_vector<expr> m_new_core;
mus m_mus;
expr_ref_vector m_trail;
@ -63,14 +56,12 @@ public:
TRACE("opt", tout << mk_pp(e, m) << "\n";);
expr_ref asum(m), fml(m);
app_ref cls(m);
info inf(0,rational(0));
if (m_asm2info.find(e, inf)) {
inf.m_weight += w;
m_asm2info.insert(e, inf);
rational weight(0);
if (m_asm2weight.find(e, weight)) {
weight += w;
m_asm2weight.insert(e, weight);
return;
}
cls = mk_cls(e);
m_trail.push_back(cls);
if (is_literal(e)) {
asum = e;
}
@ -79,21 +70,18 @@ public:
fml = m.mk_iff(asum, e);
m_s->assert_expr(fml);
}
new_assumption(asum, cls, w);
new_assumption(asum, w);
m_upper += w;
}
void new_assumption(expr* e, app* cls, rational const& w) {
void new_assumption(expr* e, rational const& w) {
TRACE("opt", tout << "insert: " << mk_pp(e, m) << " : " << w << "\n";);
info inf(cls, w);
m_asm2info.insert(e, inf);
m_asm2weight.insert(e, w);
m_asms.push_back(e);
m_trail.push_back(e);
}
lbool operator()() {
expr_ref fml(m);
ptr_vector<expr> core;
solver::scoped_push _sc(*m_s.get());
init();
init_local();
@ -125,28 +113,13 @@ public:
m_upper = m_lower;
return l_true;
}
case l_false:
is_sat = process_unsat();
if (is_sat != l_true) return is_sat;
break;
case l_undef:
return l_undef;
default:
core.reset();
m_s->get_unsat_core(core);
TRACE("opt", display_vec(tout << "core: ", core.size(), core.c_ptr()););
SASSERT(!core.empty());
is_sat = minimize_core(core);
SASSERT(!core.empty());
if (core.empty()) {
return l_false;
}
if (is_sat != l_true) {
return is_sat;
}
remove_core(core);
rational w = split_core(core);
TRACE("opt", display_vec(tout << "minimized core: ", core.size(), core.c_ptr()););
max_resolve(core, w);
fml = m.mk_not(m.mk_and(m_B.size(), m_B.c_ptr()));
m_s->assert_expr(fml);
m_lower += w;
break;
}
IF_VERBOSE(1, verbose_stream() << "(opt.max_res [" << m_lower << ":" << m_upper << "])\n";);
@ -154,13 +127,78 @@ public:
return l_true;
}
lbool get_cores(vector<ptr_vector<expr> >& cores) {
// assume m_s is unsat.
lbool is_sat = l_false;
expr_ref_vector asms(m_asms);
cores.reset();
ptr_vector<expr> core;
while (is_sat == l_false) {
core.reset();
m_s->get_unsat_core(core);
is_sat = minimize_core(core);
if (is_sat != l_true) {
break;
}
cores.push_back(core);
// TBD: ad hoc to avoid searching for large cores..
if (core.size() >= 3) {
break;
}
remove_soft(core, asms);
TRACE("opt",
display_vec(tout << "core: ", core.size(), core.c_ptr());
display_vec(tout << "assumptions: ", asms.size(), asms.c_ptr()););
is_sat = m_s->check_sat(asms.size(), asms.c_ptr());
}
TRACE("opt",
tout << "num cores: " << cores.size() << "\n";
for (unsigned i = 0; i < cores.size(); ++i) {
for (unsigned j = 0; j < cores[i].size(); ++j) {
tout << mk_pp(cores[i][j], m) << " ";
}
tout << "\n";
}
tout << "num satisfying: " << asms.size() << "\n";);
return is_sat;
}
lbool process_unsat() {
vector<ptr_vector<expr> > cores;
lbool is_sat = get_cores(cores);
if (is_sat != l_true) {
return is_sat;
}
if (cores.empty()) {
return l_false;
}
for (unsigned i = 0; is_sat == l_true && i < cores.size(); ++i) {
is_sat = process_unsat(cores[i]);
}
return is_sat;
}
lbool process_unsat(ptr_vector<expr>& core) {
expr_ref fml(m);
remove_core(core);
rational w = split_core(core);
TRACE("opt", display_vec(tout << "minimized core: ", core.size(), core.c_ptr()););
max_resolve(core, w);
fml = m.mk_not(m.mk_and(m_B.size(), m_B.c_ptr()));
m_s->assert_expr(fml);
m_lower += w;
return l_true;
}
lbool minimize_core(ptr_vector<expr>& core) {
if (m_sat_enabled) {
return l_true;
}
m_mus.reset();
for (unsigned i = 0; i < core.size(); ++i) {
app* cls = get_clause(core[i]);
SASSERT(cls);
SASSERT(m.is_or(cls));
m_mus.add_soft(core[i], cls->get_num_args(), cls->get_args());
m_mus.add_soft(core[i]);
}
unsigned_vector mus_idx;
lbool is_sat = m_mus.get_mus(mus_idx);
@ -177,11 +215,7 @@ public:
}
rational get_weight(expr* e) {
return m_asm2info.find(e).m_weight;
}
app* get_clause(expr* e) {
return m_asm2info.find(e).m_cls;
return m_asm2weight.find(e);
}
rational split_core(ptr_vector<expr> const& core) {
@ -200,7 +234,7 @@ public:
rational w2 = get_weight(core[i]);
if (w2 > w) {
rational w3 = w2 - w;
new_assumption(core[i], get_clause(core[i]), w3);
new_assumption(core[i], w3);
}
}
return w;
@ -246,55 +280,25 @@ public:
asum = mk_fresh_bool("a");
cls = m.mk_or(b_i1, d);
fml = m.mk_iff(asum, cls);
cls = mk_cls(cls);
m_trail.push_back(cls);
new_assumption(asum, cls, w);
new_assumption(asum, w);
m_s->assert_expr(fml);
}
}
app_ref mk_cls(expr* e) {
expr_ref_vector disj(m), todo(m);
expr_ref f(m);
app_ref result(m);
expr* e1, *e2;
todo.push_back(e);
while (!todo.empty()) {
f = todo.back();
todo.pop_back();
if (m.is_implies(f, e1, e2)) {
todo.push_back(m.mk_not(e1));
todo.push_back(e2);
}
else if (m.is_not(f, e1) && m.is_not(e1, e2)) {
todo.push_back(e2);
}
else if (m.is_or(f)) {
todo.append(to_app(f)->get_num_args(), to_app(f)->get_args());
}
else if (m.is_not(f, e1) && m.is_and(e1)) {
for (unsigned i = 0; i < to_app(e1)->get_num_args(); ++i) {
todo.push_back(m.mk_not(to_app(e1)->get_arg(i)));
}
}
else {
disj.push_back(f);
}
}
result = m.mk_or(disj.size(), disj.c_ptr());
return result;
}
void remove_core(ptr_vector<expr> const& core) {
for (unsigned i = 0; i < m_asms.size(); ++i) {
if (core.contains(m_asms[i].get())) {
m_asms[i] = m_asms.back();
m_asms.pop_back();
void remove_soft(ptr_vector<expr> const& core, expr_ref_vector& asms) {
for (unsigned i = 0; i < asms.size(); ++i) {
if (core.contains(asms[i].get())) {
asms[i] = asms.back();
asms.pop_back();
--i;
}
}
}
void remove_core(ptr_vector<expr> const& core) {
remove_soft(core, m_asms);
}
virtual void set_cancel(bool f) {
maxsmt_solver_base::set_cancel(f);
m_mus.set_cancel(f);
@ -303,7 +307,6 @@ public:
void init_local() {
m_upper.reset();
m_lower.reset();
m_asm2info.reset();
m_trail.reset();
for (unsigned i = 0; i < m_soft.size(); ++i) {
add_soft(m_soft[i].get(), m_weights[i]);