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experiment with point-based generalization method

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-06-21 16:23:37 -07:00
parent 9489c9b08b
commit 5b5a474b54
2 changed files with 105 additions and 28 deletions
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129
src/muz_qe/pdr_generalizers.cpp
View file

@ -156,40 +156,19 @@ namespace pdr {
m_sigma.push_back(m.mk_fresh_const("sigma", a.mk_real())); m_sigma.push_back(m.mk_fresh_const("sigma", a.mk_real()));
m_sigma.push_back(m.mk_fresh_const("sigma", a.mk_real())); m_sigma.push_back(m.mk_fresh_const("sigma", a.mk_real()));
} }
void core_convex_hull_generalizer::operator()(model_node& n, expr_ref_vector& core, bool& uses_level) { void core_convex_hull_generalizer::operator()(model_node& n, expr_ref_vector& core, bool& uses_level) {
method2(n, core, uses_level);
}
// use the entire region as starting point for generalization.
void core_convex_hull_generalizer::method1(model_node& n, expr_ref_vector& core, bool& uses_level) {
manager& pm = n.pt().get_pdr_manager(); manager& pm = n.pt().get_pdr_manager();
expr_ref_vector conv1(m), conv2(m), core1(m), core2(m), eqs(m); expr_ref_vector conv1(m), conv2(m), core1(m), core2(m), eqs(m);
if (core.empty()) { if (core.empty()) {
return; return;
} }
if (!m_left.contains(n.pt().head())) { add_variables(n, eqs);
expr_ref left(m), right(m);
m_left.insert(n.pt().head(), 0);
unsigned sz = n.pt().sig_size();
for (unsigned i = 0; i < sz; ++i) {
func_decl* fn0 = n.pt().sig(i);
sort* srt = fn0->get_range();
if (a.is_int_real(srt)) {
func_decl* fn1 = pm.o2n(fn0, 0);
left = m.mk_fresh_const(fn1->get_name().str().c_str(), srt);
right = m.mk_fresh_const(fn1->get_name().str().c_str(), srt);
m_left.insert(fn1, left);
m_right.insert(fn1, right);
m_trail.push_back(left);
m_trail.push_back(right);
}
}
}
unsigned sz = n.pt().sig_size();
for (unsigned i = 0; i < sz; ++i) {
expr* left, *right;
func_decl* fn0 = n.pt().sig(i);
func_decl* fn1 = pm.o2n(fn0, 0);
if (m_left.find(fn1, left) && m_right.find(fn1, right)) {
eqs.push_back(m.mk_eq(m.mk_const(fn1), a.mk_add(left, right)));
}
}
if (!mk_convex(core, 0, conv1)) { if (!mk_convex(core, 0, conv1)) {
IF_VERBOSE(0, verbose_stream() << "Non-convex: " << mk_pp(pm.mk_and(core), m) << "\n";); IF_VERBOSE(0, verbose_stream() << "Non-convex: " << mk_pp(pm.mk_and(core), m) << "\n";);
return; return;
@ -230,6 +209,100 @@ namespace pdr {
} }
} }
// take as starting point two points from different regions.
void core_convex_hull_generalizer::method2(model_node& n, expr_ref_vector& core, bool& uses_level) {
expr_ref_vector conv1(m), conv2(m), core1(m), core2(m);
if (core.empty()) {
return;
}
manager& pm = n.pt().get_pdr_manager();
smt::kernel ctx(m, m_ctx.get_fparams(), m_ctx.get_params().p);
expr_ref goal(pm.mk_and(core));
ctx.assert_expr(goal);
lbool r = ctx.check();
if (r != l_true) {
IF_VERBOSE(0, verbose_stream() << "unexpected result from satisfiability check\n";);
return;
}
add_variables(n, conv1);
model_ref mdl;
ctx.get_model(mdl);
unsigned sz = n.pt().sig_size();
for (unsigned i = 0; i < sz; ++i) {
expr_ref_vector constr(m);
expr* left, *right;
func_decl* fn0 = n.pt().sig(i);
func_decl* fn1 = pm.o2n(fn0, 0);
if (m_left.find(fn1, left) && m_right.find(fn1, right)) {
expr_ref val(m);
mdl->eval(fn1, val);
if (val) {
conv1.push_back(m.mk_eq(left, val));
constr.push_back(m.mk_eq(right, val));
}
}
expr_ref new_model = pm.mk_and(constr);
m_trail.push_back(new_model);
m_trail.push_back(goal);
m_models.insert(goal, new_model);
}
conv1.push_back(a.mk_gt(m_sigma[0].get(), a.mk_numeral(rational(0), a.mk_real())));
conv1.push_back(a.mk_gt(m_sigma[1].get(), a.mk_numeral(rational(0), a.mk_real())));
conv1.push_back(m.mk_eq(a.mk_numeral(rational(1), a.mk_real()), a.mk_add(m_sigma[0].get(), m_sigma[1].get())));
obj_map<expr, expr*>::iterator it = m_models.begin(), end = m_models.end();
for (; it != end; ++it) {
if (it->m_key == goal) {
continue;
}
conv1.push_back(it->m_value);
expr_ref state = pm.mk_and(conv1);
TRACE("pdr", tout << "Try:\n" << mk_pp(state, m) << "\n";);
model_node nd(0, state, n.pt(), n.level());
if (l_false == n.pt().is_reachable(nd, &conv2, uses_level)) {
IF_VERBOSE(0,
verbose_stream() << mk_pp(state, m) << "\n";
verbose_stream() << "Generalized to:\n" << mk_pp(pm.mk_and(conv2), m) << "\n";);
core.reset();
core.append(conv2);
return;
}
conv1.pop_back();
}
}
void core_convex_hull_generalizer::add_variables(model_node& n, expr_ref_vector& eqs) {
manager& pm = n.pt().get_pdr_manager();
if (!m_left.contains(n.pt().head())) {
expr_ref left(m), right(m);
m_left.insert(n.pt().head(), 0);
unsigned sz = n.pt().sig_size();
for (unsigned i = 0; i < sz; ++i) {
func_decl* fn0 = n.pt().sig(i);
sort* srt = fn0->get_range();
if (a.is_int_real(srt)) {
func_decl* fn1 = pm.o2n(fn0, 0);
left = m.mk_fresh_const(fn1->get_name().str().c_str(), srt);
right = m.mk_fresh_const(fn1->get_name().str().c_str(), srt);
m_left.insert(fn1, left);
m_right.insert(fn1, right);
m_trail.push_back(left);
m_trail.push_back(right);
}
}
}
unsigned sz = n.pt().sig_size();
for (unsigned i = 0; i < sz; ++i) {
expr* left, *right;
func_decl* fn0 = n.pt().sig(i);
func_decl* fn1 = pm.o2n(fn0, 0);
if (m_left.find(fn1, left) && m_right.find(fn1, right)) {
eqs.push_back(m.mk_eq(m.mk_const(fn1), a.mk_add(left, right)));
}
}
}
bool core_convex_hull_generalizer::mk_convex(expr_ref_vector const& core, unsigned index, expr_ref_vector& conv) { bool core_convex_hull_generalizer::mk_convex(expr_ref_vector const& core, unsigned index, expr_ref_vector& conv) {
conv.reset(); conv.reset();
for (unsigned i = 0; i < core.size(); ++i) { for (unsigned i = 0; i < core.size(); ++i) {

4
src/muz_qe/pdr_generalizers.h
View file

@ -80,10 +80,14 @@ namespace pdr {
expr_ref_vector m_trail; expr_ref_vector m_trail;
obj_map<func_decl, expr*> m_left; obj_map<func_decl, expr*> m_left;
obj_map<func_decl, expr*> m_right; obj_map<func_decl, expr*> m_right;
obj_map<expr, expr*> m_models;
bool mk_convex(expr_ref_vector const& core, unsigned index, expr_ref_vector& conv); bool mk_convex(expr_ref_vector const& core, unsigned index, expr_ref_vector& conv);
void mk_convex(expr* fml, unsigned index, expr_ref_vector& conv); void mk_convex(expr* fml, unsigned index, expr_ref_vector& conv);
bool mk_convex(expr* term, unsigned index, bool is_mul, expr_ref& result); bool mk_convex(expr* term, unsigned index, bool is_mul, expr_ref& result);
bool translate(func_decl* fn, unsigned index, expr_ref& result); bool translate(func_decl* fn, unsigned index, expr_ref& result);
void method1(model_node& n, expr_ref_vector& core, bool& uses_level);
void method2(model_node& n, expr_ref_vector& core, bool& uses_level);
void add_variables(model_node& n, expr_ref_vector& eqs);
public: public:
core_convex_hull_generalizer(context& ctx); core_convex_hull_generalizer(context& ctx);
virtual ~core_convex_hull_generalizer() {} virtual ~core_convex_hull_generalizer() {}