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fix bug reported in issue #193: MBQI needs to avoid instantiating data-types that contain model values in nested positions

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2015-08-13 14:29:48 +02:00
parent 702af71a2d
commit cd838e5cf4
7 changed files with 100 additions and 40 deletions

View file

@ -45,6 +45,7 @@ namespace sat {
m_R.reset();
m_L_blits.reset();
m_R_blits.reset();
m_bce_use_list.finalize();
clause * const* it = m_solver.begin_clauses();
clause * const* end = m_solver.end_clauses();
for (; it != end; ++it) {
@ -140,7 +141,6 @@ namespace sat {
for (unsigned i = 0; i < m_L.size(); ++i) {
ul.insert(*m_L[i]);
}
#define MOVE_R_TO_L \
// cheap pass: add clauses from R in order
// such that they are blocked with respect to
@ -161,6 +161,10 @@ namespace sat {
}
// expensive pass: add clauses from R as long
// as BCE produces the empty set of clauses.
m_bce_use_list.init(m_solver.num_vars());
for (unsigned i = 0; i < m_L.size(); ++i) {
m_bce_use_list.insert(*m_L[i]);
}
for (unsigned i = 0; i < m_R.size(); ++i) {
if (bce(*m_R[i])) {
m_R[i] = m_R.back();
@ -173,29 +177,29 @@ namespace sat {
m_use_list = save;
}
bool bceq::bce(clause& cls) {
bool bceq::bce(clause& cls0) {
IF_VERBOSE(1, verbose_stream() << "bce " << m_L.size() << " " << m_R.size() << " " << cls0 << "\n";);
svector<bool> live_clauses;
use_list ul;
m_use_list = &ul;
ul.init(m_solver.num_vars());
for (unsigned i = 0; i < m_L.size(); ++i) {
ul.insert(*m_L[i]);
}
ul.insert(cls);
m_use_list = &m_bce_use_list;
m_bce_use_list.insert(cls0);
svector<clause*> clauses(m_L), new_clauses;
literal_vector blits(m_L_blits), new_blits;
clauses.push_back(&cls);
clauses.push_back(&cls0);
blits.push_back(null_literal);
bool removed = false;
m_removed.reset();
do {
removed = false;
for (unsigned i = 0; i < clauses.size(); ++i) {
clause& cls = *clauses[i];
literal lit = find_blocked(cls);
if (lit != null_literal) {
m_removed.setx(cls.id(), true, false);
new_clauses.push_back(&cls);
clause& cls1 = *clauses[i];
literal lit = find_blocked(cls1);
if (lit == null_literal) {
m_bce_use_list.erase(cls1);
}
else {
IF_VERBOSE(2, verbose_stream() << "; remove " << cls1 << "\n";);
m_removed.setx(cls1.id(), true, false);
new_clauses.push_back(&cls1);
new_blits.push_back(lit);
removed = true;
clauses[i] = clauses.back();
@ -215,7 +219,7 @@ namespace sat {
m_L.append(new_clauses);
m_L_blits.append(new_blits);
}
if (!clauses.empty()) std::cout << "Number left after BCE: " << clauses.size() << "\n";
IF_VERBOSE(1, if (!clauses.empty()) verbose_stream() << "; clauses left after BCE: " << clauses.size() << "\n";);
return clauses.empty();
}
@ -442,9 +446,10 @@ namespace sat {
roots[l2.var()] = l1;
vars.push_back(l2.var());
elim_eqs elim(m_solver);
for (unsigned i = 0; i < vars.size(); ++i) {
std::cout << "var: " << vars[i] << " root: " << roots[vars[i]] << "\n";
}
IF_VERBOSE(1,
for (unsigned i = 0; i < vars.size(); ++i) {
verbose_stream() << "var: " << vars[i] << " root: " << roots[vars[i]] << "\n";
});
elim(roots, vars);
}
@ -473,7 +478,7 @@ namespace sat {
init();
pure_decompose();
post_decompose();
std::cout << "Decomposed set " << m_L.size() << " rest: " << m_R.size() << "\n";
IF_VERBOSE(1, verbose_stream() << "Decomposed set " << m_L.size() << " rest: " << m_R.size() << "\n";);
TRACE("sat",
tout << "Decomposed set " << m_L.size() << "\n";

View file

@ -21,6 +21,7 @@ Revision History:
#include"sat_types.h"
#include "union_find.h"
#include "sat_simplifier.h"
namespace sat {
@ -33,6 +34,7 @@ namespace sat {
typedef svector<bin_clause> bin_clauses;
solver & m_solver;
use_list* m_use_list;
use_list m_bce_use_list;
solver* m_s;
random_gen m_rand;
svector<clause*> m_clauses;

View file

@ -100,6 +100,7 @@ public:
virtual void set_progress_callback(progress_callback * callback) {}
virtual lbool check_sat(unsigned num_assumptions, expr * const * assumptions) {
m_solver.pop_to_base_level();
dep2asm_t dep2asm;
m_model = 0;
@ -112,6 +113,7 @@ public:
r = initialize_soft_constraints();
if (r != l_true) return r;
m_solver.display_dimacs(std::cout);
r = m_solver.check(m_asms.size(), m_asms.c_ptr());
switch (r) {
case l_true:

View file

@ -171,7 +171,7 @@ namespace smt {
sk_value = sk_term;
}
}
if (m_manager.is_model_value(sk_value))
if (contains_model_value(sk_value))
return false;
bindings.set(num_decls - i - 1, sk_value);
}
@ -190,6 +190,30 @@ namespace smt {
return true;
}
void model_checker::operator()(expr *n) {
if (m_manager.is_model_value(n)) {
throw is_model_value();
}
}
bool model_checker::contains_model_value(expr* n) {
if (m_manager.is_model_value(n)) {
return true;
}
if (is_app(n) && to_app(n)->get_num_args() == 0) {
return false;
}
m_visited.reset();
try {
for_each_expr(*this, m_visited, n);
}
catch (is_model_value) {
return true;
}
return false;
}
bool model_checker::add_blocking_clause(model * cex, expr_ref_vector & sks) {
SASSERT(cex != 0);
unsigned num_sks = sks.size();

View file

@ -80,6 +80,10 @@ namespace smt {
quantifier * get_flat_quantifier(quantifier * q);
struct is_model_value {};
expr_mark m_visited;
bool contains_model_value(expr* e);
public:
model_checker(ast_manager & m, qi_params const & p, model_finder & mf);
~model_checker();
@ -95,6 +99,9 @@ namespace smt {
void reset();
void set_cancel(bool f) { m_cancel = f; }
void operator()(expr* e);
};
};

View file

@ -83,6 +83,7 @@ namespace smt {
ast_manager & m_manager;
obj_map<expr, unsigned> m_elems; // and the associated generation
obj_map<expr, expr *> m_inv;
expr_mark m_visited;
public:
instantiation_set(ast_manager & m):m_manager(m) {}
@ -98,11 +99,11 @@ namespace smt {
obj_map<expr, unsigned> const & get_elems() const { return m_elems; }
void insert(expr * n, unsigned generation) {
if (m_elems.contains(n))
if (m_elems.contains(n) || contains_model_value(n))
return;
TRACE("model_finder", tout << mk_pp(n, m_manager) << "\n";);
m_manager.inc_ref(n);
m_elems.insert(n, generation);
CTRACE("model_finder", m_manager.is_model_value(n), tout << mk_pp(n, m_manager) << "\n";);
SASSERT(!m_manager.is_model_value(n));
}
@ -145,9 +146,10 @@ namespace smt {
obj_map<expr, unsigned>::iterator end = m_elems.end();
for (; it != end; ++it) {
expr * t = (*it).m_key;
SASSERT(!m_manager.is_model_value(t));
SASSERT(!contains_model_value(t));
unsigned gen = (*it).m_value;
expr * t_val = ev.eval(t, true);
TRACE("model_finder", tout << mk_pp(t, m_manager) << "\n";);
expr * old_t = 0;
if (m_inv.find(t_val, old_t)) {
@ -167,6 +169,30 @@ namespace smt {
obj_map<expr, expr *> const & get_inv_map() const {
return m_inv;
}
struct is_model_value {};
void operator()(expr *n) {
if (m_manager.is_model_value(n)) {
throw is_model_value();
}
}
bool contains_model_value(expr* n) {
if (m_manager.is_model_value(n)) {
return true;
}
if (is_app(n) && to_app(n)->get_num_args() == 0) {
return false;
}
m_visited.reset();
try {
for_each_expr(*this, m_visited, n);
}
catch (is_model_value) {
return true;
}
return false;
}
};
/**
@ -286,7 +312,7 @@ namespace smt {
return get_root()->m_signed_proj;
}
void mk_instatiation_set(ast_manager & m) {
void mk_instantiation_set(ast_manager & m) {
SASSERT(is_root());
m_set = alloc(instantiation_set, m);
}
@ -527,13 +553,13 @@ namespace smt {
return 0;
}
void mk_instatiation_sets() {
void mk_instantiation_sets() {
ptr_vector<node>::const_iterator it = m_nodes.begin();
ptr_vector<node>::const_iterator end = m_nodes.end();
for (; it != end; ++it) {
node * curr = *it;
if (curr->is_root()) {
curr->mk_instatiation_set(m_manager);
curr->mk_instantiation_set(m_manager);
}
}
}
@ -695,6 +721,7 @@ namespace smt {
return 0;
m_model->register_decl(k_decl, r);
SASSERT(m_model->get_const_interp(k_decl) == r);
TRACE("model_finder", tout << mk_pp(r, m_manager) << "\n";);
return r;
}
@ -1204,7 +1231,7 @@ namespace smt {
// a necessary instantiation.
enode * e_arg = n->get_arg(m_arg_i);
expr * arg = e_arg->get_owner();
A_f_i->insert(arg, e_arg->get_generation());
A_f_i->insert(arg, e_arg->get_generation());
}
}
}
@ -1225,7 +1252,7 @@ namespace smt {
if (ctx->is_relevant(n)) {
enode * e_arg = n->get_arg(m_arg_i);
expr * arg = e_arg->get_owner();
s->insert(arg, e_arg->get_generation());
s->insert(arg, e_arg->get_generation());
}
}
}
@ -3378,7 +3405,7 @@ namespace smt {
quantifier_info * qi = get_quantifier_info(q);
qi->process_auf(*(m_auf_solver.get()), m_context);
}
m_auf_solver->mk_instatiation_sets();
m_auf_solver->mk_instantiation_sets();
it = qs.begin();
for (; it != end; ++it) {
quantifier * q = *it;

View file

@ -68,17 +68,10 @@ namespace smt {
bool theory_opt::is_numeral(arith_util& a, expr* term) {
while (true) {
if (a.is_uminus(term) || a.is_to_real(term) || a.is_to_int(term)) {
term = to_app(term)->get_arg(0);
}
else if (a.is_numeral(term)) {
return true;
}
else {
return false;
}
while (a.is_uminus(term) || a.is_to_real(term) || a.is_to_int(term)) {
term = to_app(term)->get_arg(0);
}
return a.is_numeral(term);
}
};