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exposing facility to extract dependent clauses

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2015-06-22 23:36:52 +02:00 committed by Christoph M. Wintersteiger
parent 949f3f9201
commit aa4b9e68d7
3 changed files with 129 additions and 66 deletions
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123
src/smt/tactic/smt_tactic.cpp
View file

@ -23,6 +23,66 @@ Notes:
#include"smt_params_helper.hpp"
#include"rewriter_types.h"
#include"filter_model_converter.h"
#include"ast_util.h"
typedef obj_map<expr, expr *> expr2expr_map;
void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, scoped_ptr<expr2expr_map>& bool2dep, ref<filter_model_converter>& fmc) {
scoped_ptr<expr2expr_map> dep2bool;
dep2bool = alloc(expr2expr_map);
bool2dep = alloc(expr2expr_map);
ptr_vector<expr> deps;
ast_manager& m = g->m();
expr_ref_vector clause(m);
unsigned sz = g->size();
for (unsigned i = 0; i < sz; i++) {
expr * f = g->form(i);
expr_dependency * d = g->dep(i);
if (d == 0) {
clauses.push_back(f);
}
else {
// create clause (not d1 \/ ... \/ not dn \/ f) when the d's are the assumptions/dependencies of f.
clause.reset();
clause.push_back(f);
deps.reset();
m.linearize(d, deps);
SASSERT(!deps.empty()); // d != 0, then deps must not be empty
ptr_vector<expr>::iterator it = deps.begin();
ptr_vector<expr>::iterator end = deps.end();
for (; it != end; ++it) {
expr * d = *it;
if (is_uninterp_const(d) && m.is_bool(d)) {
// no need to create a fresh boolean variable for d
if (!bool2dep->contains(d)) {
assumptions.push_back(d);
bool2dep->insert(d, d);
}
clause.push_back(m.mk_not(d));
}
else {
// must normalize assumption
expr * b = 0;
if (!dep2bool->find(d, b)) {
b = m.mk_fresh_const(0, m.mk_bool_sort());
dep2bool->insert(d, b);
bool2dep->insert(b, d);
assumptions.push_back(b);
if (!fmc) {
fmc = alloc(filter_model_converter, m);
}
fmc->insert(to_app(b)->get_decl());
}
clause.push_back(m.mk_not(b));
}
}
SASSERT(clause.size() > 1);
expr_ref cls(m);
cls = mk_or(m, clauses.size(), clauses.c_ptr());
clauses.push_back(cls);
}
}
}
class smt_tactic : public tactic {
smt_params m_params;
@ -128,7 +188,6 @@ public:
}
};
typedef obj_map<expr, expr *> expr2expr_map;
virtual void operator()(goal_ref const & in,
goal_ref_buffer & result,
@ -147,65 +206,17 @@ public:
TRACE("smt_tactic_memory", tout << "wasted_size: " << m.get_allocator().get_wasted_size() << "\n";);
scoped_init_ctx init(*this, m);
SASSERT(m_ctx != 0);
scoped_ptr<expr2expr_map> dep2bool;
scoped_ptr<expr2expr_map> bool2dep;
ptr_vector<expr> assumptions;
expr_ref_vector clauses(m);
scoped_ptr<expr2expr_map> bool2dep;
ptr_vector<expr> assumptions;
ref<filter_model_converter> fmc;
if (in->unsat_core_enabled()) {
if (in->proofs_enabled())
throw tactic_exception("smt tactic does not support simultaneous generation of proofs and unsat cores");
dep2bool = alloc(expr2expr_map);
bool2dep = alloc(expr2expr_map);
ptr_vector<expr> deps;
ptr_vector<expr> clause;
unsigned sz = in->size();
for (unsigned i = 0; i < sz; i++) {
expr * f = in->form(i);
expr_dependency * d = in->dep(i);
if (d == 0) {
m_ctx->assert_expr(f);
}
else {
// create clause (not d1 \/ ... \/ not dn \/ f) when the d's are the assumptions/dependencies of f.
clause.reset();
clause.push_back(f);
deps.reset();
m.linearize(d, deps);
SASSERT(!deps.empty()); // d != 0, then deps must not be empty
ptr_vector<expr>::iterator it = deps.begin();
ptr_vector<expr>::iterator end = deps.end();
for (; it != end; ++it) {
expr * d = *it;
if (is_uninterp_const(d) && m.is_bool(d)) {
// no need to create a fresh boolean variable for d
if (!bool2dep->contains(d)) {
assumptions.push_back(d);
bool2dep->insert(d, d);
}
clause.push_back(m.mk_not(d));
}
else {
// must normalize assumption
expr * b = 0;
if (!dep2bool->find(d, b)) {
b = m.mk_fresh_const(0, m.mk_bool_sort());
dep2bool->insert(d, b);
bool2dep->insert(b, d);
assumptions.push_back(b);
if (!fmc) {
fmc = alloc(filter_model_converter, m);
}
fmc->insert(to_app(b)->get_decl());
}
clause.push_back(m.mk_not(b));
}
}
SASSERT(clause.size() > 1);
expr_ref cls(m);
cls = m.mk_or(clause.size(), clause.c_ptr());
m_ctx->assert_expr(cls);
}
extract_clauses_and_dependencies(in, clauses, assumptions, bool2dep, fmc);
for (unsigned i = 0; i < clauses.size(); ++i) {
m_ctx->assert_expr(clauses[i].get());
}
}
else if (in->proofs_enabled()) {

8
src/smt/tactic/smt_tactic.h
View file

@ -20,15 +20,21 @@ Notes:
#define _SMT_TACTIC_H_
#include"params.h"
#include"ast.h"
#include"obj_hashtable.h"
#include"goal.h"
class tactic;
class filter_model_converter;
tactic * mk_smt_tactic(params_ref const & p = params_ref());
// syntax sugar for using_params(mk_smt_tactic(), p) where p = (:auto_config, auto_config)
tactic * mk_smt_tactic_using(bool auto_config = true, params_ref const & p = params_ref());
void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, scoped_ptr<obj_map<expr, expr*> >& bool2dep, ref<filter_model_converter>& fmc);
/*
ADD_TACTIC("smt", "apply a SAT based SMT solver.", "mk_smt_tactic(p)")
*/
#endif

64
src/tactic/nlsat_smt/nl_purify_tactic.cpp
View file

@ -115,8 +115,6 @@ public:
arith_util & u() { return m_owner.m_util; }
bool produce_proofs() const { return m_owner.m_produce_proofs; }
expr * mk_interface_var(expr* arg) {
expr* r;
if (m_interface_cache.find(arg, r)) {
@ -145,7 +143,7 @@ public:
return is_app(e) && (to_app(e)->get_family_id() == u().get_family_id());
}
void mk_interface_bool(func_decl * f, unsigned num, expr* const* args, expr_ref& result) {
void mk_interface_bool(func_decl * f, unsigned num, expr* const* args, expr_ref& result, proof_ref& pr) {
expr_ref old_pred(m.mk_app(f, num, args), m);
polarity_t pol;
VERIFY(m_polarities.find(old_pred, pol));
@ -154,10 +152,13 @@ public:
m_new_preds.push_back(to_app(result));
m_owner.m_fmc->insert(to_app(result)->get_decl());
if (pol != pol_neg) {
m_owner.m_nl_g->assert_expr(m.mk_or(m.mk_not(result), m.mk_app(f, num, args)));
m_owner.m_nl_g->assert_expr(m.mk_or(m.mk_not(result), old_pred));
}
if (pol != pol_pos) {
m_owner.m_nl_g->assert_expr(m.mk_or(result, m.mk_not(m.mk_app(f, num, args))));
m_owner.m_nl_g->assert_expr(m.mk_or(result, m.mk_not(old_pred)));
}
if (m_owner.m_produce_proofs) {
pr = m.mk_oeq(old_pred, result);
}
TRACE("nlsat_smt", tout << old_pred << " : " << result << "\n";);
}
@ -183,7 +184,7 @@ public:
br_status reduce_app_bool(func_decl * f, unsigned num, expr* const* args, expr_ref& result, proof_ref & pr) {
if (f->get_family_id() == m.get_basic_family_id()) {
if (f->get_decl_kind() == OP_EQ && u().is_real(args[0])) {
mk_interface_bool(f, num, args, result);
mk_interface_bool(f, num, args, result, pr);
return BR_DONE;
}
else {
@ -194,7 +195,7 @@ public:
switch (f->get_decl_kind()) {
case OP_LE: case OP_GE: case OP_LT: case OP_GT:
// these are the only real cases of non-linear atomic formulas besides equality.
mk_interface_bool(f, num, args, result);
mk_interface_bool(f, num, args, result, pr);
return BR_DONE;
default:
return BR_FAILED;
@ -209,12 +210,14 @@ public:
bool is_arith_op(expr* e) {
return is_app(e) && to_app(e)->get_family_id() == u().get_family_id();
}
br_status reduce_app_real(func_decl * f, unsigned num, expr* const* args, expr_ref& result, proof_ref & pr) {
bool has_interface = false;
bool is_arith = false;
if (f->get_family_id() == u().get_family_id()) {
switch (f->get_decl_kind()) {
case OP_NUM: case OP_IRRATIONAL_ALGEBRAIC_NUM:
case OP_NUM:
case OP_IRRATIONAL_ALGEBRAIC_NUM:
return BR_FAILED;
default:
is_arith = true;
@ -238,6 +241,9 @@ public:
}
if (has_interface) {
result = m.mk_app(f, num, m_args.c_ptr());
if (m_owner.m_produce_proofs) {
pr = m.mk_oeq(m.mk_app(f, num, args), result); // push proof object to mk_interface_var?
}
TRACE("nlsat_smt", tout << result << "\n";);
return BR_DONE;
}
@ -264,6 +270,7 @@ private:
}
};
arith_util & u() { return m_util; }
void check_point() {
@ -727,7 +734,6 @@ public:
r.set_bool_mode();
rewrite_goal(r, g);
g->inc_depth();
for (unsigned i = 0; i < g->size(); ++i) {
m_solver->assert_expr(g->form(i));
}
@ -740,3 +746,43 @@ public:
tactic * mk_nl_purify_tactic(ast_manager& m, params_ref const& p) {
return alloc(nl_purify_tactic, m, p);
}
#if 0
void mark_interface_vars(goal_ref const& g) {
expr_mark visited;
ptr_vector<expr> todo;
unsigned sz = g->size();
for (unsigned i = 0; i < sz; i++) {
todo.push_back(g->form(i));
}
while (!todo.empty()) {
expr* e = todo.back();
todo.pop_back();
if (visited.is_marked(e)) {
continue;
}
visited.mark(e);
if (is_quantifier(e)) {
todo.push_back(to_quantifier(e)->get_expr());
continue;
}
if (is_var(e)) {
continue;
}
app* ap = to_app(e);
sz = ap->get_num_args();
bool is_arith = is_arith_op(e);
for (unsigned i = 0; i < sz; ++i) {
expr* arg = ap->get_arg(i);
todo.push_back(arg);
if (is_arith && !is_arith_op(arg)) {
m_interface_vars.mark(arg);
}
else if (!is_arith && is_arith_op(arg) && ap->get_family_id() != m.get_basic_family_id()) {
m_interface_vars.mark(arg);
}
}
}
}
#endif