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fix mb maximization logic, so far not accessible

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2016-06-20 16:39:03 -07:00
parent c7ff05cc78
commit 9c099d6b1b
12 changed files with 318 additions and 109 deletions
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149
src/math/simplex/model_based_opt.cpp
View file

@ -41,7 +41,6 @@ namespace opt {
bool model_based_opt::invariant() {
// variables in each row are sorted.
for (unsigned i = 0; i < m_rows.size(); ++i) {
if (!invariant(i, m_rows[i])) {
return false;
@ -50,19 +49,21 @@ namespace opt {
return true;
}
#define PASSERT(_e_) if (!(_e_)) { TRACE("opt", display(tout, r);); SASSERT(_e_); }
bool model_based_opt::invariant(unsigned index, row const& r) {
rational val = r.m_coeff;
vector<var> const& vars = r.m_vars;
for (unsigned i = 0; i < vars.size(); ++i) {
var const& v = vars[i];
SASSERT(i + 1 == vars.size() || v.m_id < vars[i+1].m_id);
SASSERT(!v.m_coeff.is_zero());
val += v.m_coeff * m_var2value[v.m_id];
// variables in each row are sorted and have non-zero coefficients
SASSERT(i + 1 == vars.size() || vars[i].m_id < vars[i+1].m_id);
SASSERT(!vars[i].m_coeff.is_zero());
}
SASSERT(val == r.m_value);
SASSERT(r.m_type != t_eq || val.is_zero());
SASSERT(index == 0 || r.m_type != t_lt || val.is_neg());
SASSERT(index == 0 || r.m_type != t_le || !val.is_pos());
PASSERT(r.m_value == get_row_value(r));
PASSERT(r.m_type != t_eq || r.m_value.is_zero());
// values satisfy constraints
PASSERT(index == 0 || r.m_type != t_lt || r.m_value.is_neg());
PASSERT(index == 0 || r.m_type != t_le || !r.m_value.is_pos());
return true;
}
@ -90,20 +91,25 @@ namespace opt {
//
inf_eps model_based_opt::maximize() {
SASSERT(invariant());
unsigned_vector other;
unsigned_vector bound_trail, bound_vars;
TRACE("opt", display(tout << "tableau\n"););
while (!objective().m_vars.empty()) {
TRACE("opt", display(tout << "tableau\n"););
var v = objective().m_vars.back();
unsigned x = v.m_id;
rational const& coeff = v.m_coeff;
unsigned bound_row_index;
rational bound_coeff;
other.reset();
if (find_bound(x, bound_row_index, bound_coeff, other, coeff.is_pos())) {
if (find_bound(x, bound_row_index, bound_coeff, coeff.is_pos())) {
SASSERT(!bound_coeff.is_zero());
for (unsigned i = 0; i < other.size(); ++i) {
resolve(bound_row_index, bound_coeff, other[i], x);
TRACE("opt", display(tout << "update: " << v << " ", objective());
for (unsigned i = 0; i < m_above.size(); ++i) {
display(tout << "resolve: ", m_rows[m_above[i]]);
});
for (unsigned i = 0; i < m_above.size(); ++i) {
resolve(bound_row_index, bound_coeff, m_above[i], x);
}
for (unsigned i = 0; i < m_below.size(); ++i) {
resolve(bound_row_index, bound_coeff, m_below[i], x);
}
// coeff*x + objective <= ub
// a2*x + t2 <= 0
@ -116,6 +122,8 @@ namespace opt {
bound_vars.push_back(x);
}
else {
TRACE("opt", display(tout << "unbound: " << v << " ", objective()););
update_values(bound_vars, bound_trail);
return inf_eps::infinity();
}
}
@ -136,15 +144,33 @@ namespace opt {
}
void model_based_opt::update_value(unsigned x, rational const& val) {
rational old_val = m_var2value[x];
m_var2value[x] = val;
unsigned_vector const& row_ids = m_var2row_ids[x];
for (unsigned i = 0; i < row_ids.size(); ++i) {
unsigned row_id = row_ids[i];
rational coeff = get_coefficient(row_id, x);
if (coeff.is_zero()) {
continue;
}
row & r = m_rows[row_id];
rational delta = coeff * (val - old_val);
r.m_value += delta;
SASSERT(invariant(row_id, r));
}
}
void model_based_opt::update_values(unsigned_vector const& bound_vars, unsigned_vector const& bound_trail) {
rational eps(0);
for (unsigned i = bound_trail.size(); i > 0; ) {
--i;
unsigned x = bound_vars[i];
row& r = m_rows[bound_trail[i]];
rational val = r.m_coeff;
rational x_val;
rational x_coeff;
rational old_x_val = m_var2value[x];
rational new_x_val;
rational x_coeff, eps(0);
vector<var> const& vars = r.m_vars;
for (unsigned j = 0; j < vars.size(); ++j) {
var const& v = vars[j];
@ -155,28 +181,21 @@ namespace opt {
val += m_var2value[v.m_id]*v.m_coeff;
}
}
TRACE("opt", display(tout << "v" << x << " val: " << val
<< " coeff_x: " << x_coeff << " val_x: " << m_var2value[x] << " ", r); );
SASSERT(!x_coeff.is_zero());
x_val = -val/x_coeff;
//
//
// ax + t < 0
// <=> x < -t/a
// <=> x := -t/a - epsilon
//
if (r.m_type == t_lt) {
// Adjust epsilon to be
if (!x_val.is_zero() && (eps.is_zero() || eps >= abs(x_val))) {
eps = abs(x_val)/rational(2);
}
if (!r.m_value.is_zero() && (eps.is_zero() || eps >= abs(r.m_value))) {
eps = abs(r.m_value)/rational(2);
}
new_x_val = -val/x_coeff;
if (r.m_type == t_lt) {
eps = abs(old_x_val - new_x_val)/rational(2);
eps = std::min(rational::one(), eps);
SASSERT(!eps.is_zero());
//
// ax + t < 0
// <=> x < -t/a
// <=> x := -t/a - epsilon
//
if (x_coeff.is_pos()) {
x_val -= eps;
new_x_val -= eps;
}
//
// -ax + t < 0
@ -185,27 +204,47 @@ namespace opt {
// <=> x > t/a
// <=> x := t/a + epsilon
//
else if (x_coeff.is_neg()) {
x_val += eps;
else {
new_x_val += eps;
}
}
m_var2value[x] = x_val;
r.m_value = (x_val * x_coeff) + val;
TRACE("opt", display(tout << "v" << x
<< " coeff_x: " << x_coeff
<< " old_x_val: " << old_x_val
<< " new_x_val: " << new_x_val
<< " eps: " << eps << " ", r); );
m_var2value[x] = new_x_val;
TRACE("opt", display(tout << "v" << x << " val: " << val << " coeff_x: "
<< x_coeff << " val_x: " << m_var2value[x] << " ", r); );
r.m_value = get_row_value(r);
SASSERT(invariant(bound_trail[i], r));
}
// update and check bounds for all other affected rows.
for (unsigned i = bound_trail.size(); i > 0; ) {
--i;
unsigned x = bound_vars[i];
unsigned_vector const& row_ids = m_var2row_ids[x];
for (unsigned j = 0; j < row_ids.size(); ++j) {
unsigned row_id = row_ids[j];
row & r = m_rows[row_id];
r.m_value = get_row_value(r);
SASSERT(invariant(row_id, r));
}
}
SASSERT(invariant());
}
bool model_based_opt::find_bound(unsigned x, unsigned& bound_row_index, rational& bound_coeff, unsigned_vector& other, bool is_pos) {
bool model_based_opt::find_bound(unsigned x, unsigned& bound_row_index, rational& bound_coeff, bool is_pos) {
bound_row_index = UINT_MAX;
rational lub_val;
rational const& x_val = m_var2value[x];
unsigned_vector const& row_ids = m_var2row_ids[x];
uint_set visited;
m_above.reset();
m_below.reset();
for (unsigned i = 0; i < row_ids.size(); ++i) {
unsigned row_id = row_ids[i];
SASSERT(row_id != m_objective_id);
if (visited.contains(row_id)) {
continue;
}
@ -226,24 +265,34 @@ namespace opt {
else if ((value == lub_val && r.m_type == opt::t_lt) ||
(is_pos && value < lub_val) ||
(!is_pos && value > lub_val)) {
other.push_back(bound_row_index);
m_above.push_back(bound_row_index);
lub_val = value;
bound_row_index = row_id;
bound_row_index = row_id;
bound_coeff = a;
}
else {
other.push_back(row_id);
m_above.push_back(row_id);
}
}
else {
r.m_alive = false;
m_below.push_back(row_id);
}
}
}
return bound_row_index != UINT_MAX;
}
rational model_based_opt::get_coefficient(unsigned row_id, unsigned var_id) {
rational model_based_opt::get_row_value(row const& r) const {
vector<var> const& vars = r.m_vars;
rational val = r.m_coeff;
for (unsigned i = 0; i < vars.size(); ++i) {
var const& v = vars[i];
val += v.m_coeff * m_var2value[v.m_id];
}
return val;
}
rational model_based_opt::get_coefficient(unsigned row_id, unsigned var_id) const {
row const& r = m_rows[row_id];
if (r.m_vars.empty()) {
return rational::zero();

14
src/math/simplex/model_based_opt.h
View file

@ -65,24 +65,29 @@ namespace opt {
vector<rational> m_var2value;
vector<var> m_new_vars;
unsigned_vector m_lub, m_glb;
unsigned_vector m_above, m_below;
bool invariant();
bool invariant(unsigned index, row const& r);
row& objective() { return m_rows[0]; }
bool find_bound(unsigned x, unsigned& bound_index, rational& bound_coeff, unsigned_vector& other, bool is_pos);
bool find_bound(unsigned x, unsigned& bound_index, rational& bound_coeff, bool is_pos);
rational get_coefficient(unsigned row_id, unsigned var_id);
rational get_coefficient(unsigned row_id, unsigned var_id) const;
rational get_row_value(row const& r) const;
void resolve(unsigned row_src, rational const& a1, unsigned row_dst, unsigned x);
void mul_add(bool same_sign, unsigned row_id1, rational const& c, unsigned row_id2);
void set_row(unsigned row_id, vector<var> const& coeffs, rational const& c, ineq_type rel);
void set_row(unsigned row_id, vector<var> const& coeffs, rational const& c, ineq_type rel);
void update_values(unsigned_vector const& bound_vars, unsigned_vector const& bound_trail);
void update_value(unsigned x, rational const& val);
void project(unsigned var);
void solve_for(unsigned row_id, unsigned x);
@ -132,5 +137,6 @@ namespace opt {
std::ostream& operator<<(std::ostream& out, opt::ineq_type ie);
inline std::ostream& operator<<(std::ostream& out, opt::model_based_opt::var const v) { return out << "v" << v.m_id; }
#endif

8
src/opt/opt_context.cpp
View file

@ -225,7 +225,7 @@ namespace opt {
normalize();
internalize();
update_solver();
#if 1
#if 0
if (is_qsat_opt()) {
return run_qsat_opt();
}
@ -367,6 +367,7 @@ namespace opt {
lbool context::execute_box() {
if (m_box_index < m_objectives.size()) {
SASSERT(m_box_index < m_box_models.size());
m_model = m_box_models[m_box_index];
++m_box_index;
return l_true;
@ -383,7 +384,9 @@ namespace opt {
if (obj.m_type == O_MAXSMT) {
solver::scoped_push _sp(get_solver());
r = execute(obj, false, false);
if (r == l_true) m_box_models.push_back(m_model.get());
if (r == l_true) {
m_box_models.push_back(m_model.get());
}
}
else {
m_box_models.push_back(m_optsmt.get_model(j));
@ -391,6 +394,7 @@ namespace opt {
}
}
if (r == l_true && m_objectives.size() > 0) {
SASSERT(!m_box_models.empty());
m_model = m_box_models[0];
}
return r;

3
src/opt/opt_params.pyg
View file

@ -1,8 +1,7 @@
def_module_params('opt',
description='optimization parameters',
export=True,
params=(('timeout', UINT, UINT_MAX, 'set timeout'),
('optsmt_engine', SYMBOL, 'basic', "select optimization engine: 'basic', 'farkas', 'symba'"),
params=(('optsmt_engine', SYMBOL, 'basic', "select optimization engine: 'basic', 'farkas', 'symba'"),
('maxsat_engine', SYMBOL, 'maxres', "select engine for maxsat: 'fu_malik', 'core_maxsat', 'wmax', 'pbmax', 'maxres', 'pd-maxres', 'bcd2', 'wpm2', 'sls', 'maxhs'"),
('priority', SYMBOL, 'lex', "select how to priortize objectives: 'lex' (lexicographic), 'pareto', or 'box'"),
('dump_benchmarks', BOOL, False, 'dump benchmarks for profiling'),

63
src/qe/qe_arith.cpp
View file

@ -105,7 +105,10 @@ namespace qe {
expr_ref t(m);
opt::ineq_type ty = opt::t_le;
expr* e1, *e2;
DEBUG_CODE(expr_ref val(m); VERIFY(model.eval(lit, val) && m.is_true(val)););
DEBUG_CODE(expr_ref val(m);
VERIFY(model.eval(lit, val));
CTRACE("qe", !m.is_true(val), tout << mk_pp(lit, m) << " := " << val << "\n";);
SASSERT(m.is_true(val)););
bool is_not = m.is_not(lit, lit);
if (is_not) {
@ -942,7 +945,7 @@ namespace qe {
SASSERT(m_u < m_delta && rational(0) <= m_u);
for (unsigned i = 0; i < n; ++i) {
add_lit(model, lits, mk_divides(div_divisor(i),
mk_add(mk_num(div_coeff(i) * m_u), div_term(i))));
mk_add(mk_num(div_coeff(i) * m_u), div_term(i))));
}
reset_divs();
//
@ -1070,7 +1073,7 @@ namespace qe {
for (unsigned i = 0; i < rows.size(); ++i) {
expr_ref_vector ts(m);
expr_ref t(m), s(m);
expr_ref t(m), s(m), val(m);
row const& r = rows[i];
if (r.m_vars.size() == 0) {
continue;
@ -1088,6 +1091,8 @@ namespace qe {
case opt::t_eq: t = a.mk_eq(t, s); break;
}
fmls.push_back(t);
VERIFY(model.eval(t, val));
CTRACE("qe", !m.is_true(val), tout << "Evaluated unit " << t << " to " << val << "\n";);
continue;
}
for (j = 0; j < r.m_vars.size(); ++j) {
@ -1111,10 +1116,16 @@ namespace qe {
case opt::t_eq: t = a.mk_eq(t, s); break;
}
fmls.push_back(t);
VERIFY(model.eval(t, val));
CTRACE("qe", !m.is_true(val), tout << "Evaluated " << t << " to " << val << "\n";);
}
}
opt::inf_eps maximize(expr_ref_vector const& fmls0, model& mdl, app* t, expr_ref& bound) {
opt::inf_eps maximize(expr_ref_vector const& fmls0, model& mdl, app* t, expr_ref& ge, expr_ref& gt) {
validate_model(mdl, fmls0);
m_trail.reset();
SASSERT(a.is_real(t));
expr_ref_vector fmls(fmls0);
@ -1139,11 +1150,6 @@ namespace qe {
// find optimal value
value = mbo.maximize();
expr_ref val(a.mk_numeral(value.get_rational(), false), m);
if (!value.is_finite()) {
bound = m.mk_false();
return value;
}
// update model to use new values that satisfy optimality
ptr_vector<expr> vars;
@ -1160,17 +1166,42 @@ namespace qe {
TRACE("qe", tout << "omitting model update for non-uninterpreted constant " << mk_pp(e, m) << "\n";);
}
}
expr_ref val(a.mk_numeral(value.get_rational(), false), m);
expr_ref tval(m);
VERIFY (mdl.eval(t, tval));
// update the predicate 'bound' which forces larger values.
if (value.get_infinitesimal().is_neg()) {
bound = a.mk_le(val, t);
// update the predicate 'bound' which forces larger values when 'strict' is true.
// strict: bound := valuue < t
// !strict: bound := value <= t
if (!value.is_finite()) {
ge = a.mk_ge(t, tval);
gt = m.mk_false();
}
else if (value.get_infinitesimal().is_neg()) {
ge = a.mk_ge(t, tval);
gt = a.mk_ge(t, val);
}
else {
bound = a.mk_lt(val, t);
}
ge = a.mk_ge(t, val);
gt = a.mk_gt(t, val);
}
validate_model(mdl, fmls0);
return value;
}
bool validate_model(model& mdl, expr_ref_vector const& fmls) {
bool valid = true;
for (unsigned i = 0; i < fmls.size(); ++i) {
expr_ref val(m);
VERIFY(mdl.eval(fmls[i], val));
if (!m.is_true(val)) {
valid = false;
TRACE("qe", tout << mk_pp(fmls[i], m) << " := " << val << "\n";);
}
}
return valid;
}
void extract_coefficients(opt::model_based_opt& mbo, model& model, obj_map<expr, rational> const& ts, obj_map<expr, unsigned>& tids, vars& coeffs) {
coeffs.reset();
obj_map<expr, rational>::iterator it = ts.begin(), end = ts.end();
@ -1219,8 +1250,8 @@ namespace qe {
return m_imp->a.get_family_id();
}
opt::inf_eps arith_project_plugin::maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& bound) {
return m_imp->maximize(fmls, mdl, t, bound);
opt::inf_eps arith_project_plugin::maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& ge, expr_ref& gt) {
return m_imp->maximize(fmls, mdl, t, ge, gt);
}
bool arith_project(model& model, app* var, expr_ref_vector& lits) {

2
src/qe/qe_arith.h
View file

@ -32,7 +32,7 @@ namespace qe {
virtual void operator()(model& model, app_ref_vector& vars, expr_ref_vector& lits);
opt::inf_eps maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& bound);
opt::inf_eps maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& ge, expr_ref& gt);
};
bool arith_project(model& model, app* var, expr_ref_vector& lits);

19
src/qe/qe_mbp.cpp
View file

@ -285,9 +285,9 @@ class mbp::impl {
public:
opt::inf_eps maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& bound) {
opt::inf_eps maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& ge, expr_ref& gt) {
arith_project_plugin arith(m);
return arith.maximize(fmls, mdl, t, bound);
return arith.maximize(fmls, mdl, t, ge, gt);
}
void extract_literals(model& model, expr_ref_vector& fmls) {
@ -428,7 +428,16 @@ public:
}
}
bool validate_model(model& model, expr_ref_vector const& fmls) {
expr_ref val(m);
for (unsigned i = 0; i < fmls.size(); ++i) {
VERIFY(model.eval(fmls[i], val) && m.is_true(val));
}
return true;
}
void operator()(bool force_elim, app_ref_vector& vars, model& model, expr_ref_vector& fmls) {
SASSERT(validate_model(model, fmls));
expr_ref val(m), tmp(m);
app_ref var(m);
expr_ref_vector unused_fmls(m);
@ -446,6 +455,7 @@ public:
}
}
while (!vars.empty() && !fmls.empty()) {
std::cout << "mbp: " << var << "\n";
var = vars.back();
vars.pop_back();
project_plugin* p = get_plugin(var);
@ -483,6 +493,7 @@ public:
vars.reset();
}
fmls.append(unused_fmls);
SASSERT(validate_model(model, fmls));
TRACE("qe", tout << vars << " " << fmls << "\n";);
}
@ -508,6 +519,6 @@ void mbp::extract_literals(model& model, expr_ref_vector& lits) {
m_impl->extract_literals(model, lits);
}
opt::inf_eps mbp::maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& bound) {
return m_impl->maximize(fmls, mdl, t, bound);
opt::inf_eps mbp::maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& ge, expr_ref& gt) {
return m_impl->maximize(fmls, mdl, t, ge, gt);
}

2
src/qe/qe_mbp.h
View file

@ -79,7 +79,7 @@ namespace qe {
\brief
Maximize objective t under current model for constraints in fmls.
*/
opt::inf_eps maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& bound);
opt::inf_eps maximize(expr_ref_vector const& fmls, model& mdl, app* t, expr_ref& ge, expr_ref& gt);
};
}

127
src/qe/qsat.cpp
View file

@ -507,6 +507,26 @@ namespace qe {
}
}
bool pred_abs::validate_defs(model& model) const {
bool valid = true;
obj_map<expr, expr*>::iterator it = m_pred2lit.begin(), end = m_pred2lit.end();
for (; it != end; ++it) {
expr_ref val_a(m), val_b(m);
expr* a = it->m_key;
expr* b = it->m_value;
VERIFY(model.eval(a, val_a));
VERIFY(model.eval(b, val_b));
if (val_a != val_b) {
TRACE("qe",
tout << mk_pp(a, m) << " := " << val_a << "\n";
tout << mk_pp(b, m) << " := " << val_b << "\n";
tout << m_elevel.find(a) << "\n";);
valid = false;
}
}
return valid;
}
class kernel {
ast_manager& m;
params_ref m_params;
@ -575,6 +595,9 @@ namespace qe {
app* m_objective;
opt::inf_eps* m_value;
bool m_was_sat;
model_ref m_model_save;
expr_ref m_gt;
opt::inf_eps m_value_save;
/**
@ -588,15 +611,23 @@ namespace qe {
check_cancel();
expr_ref_vector asms(m_asms);
m_pred_abs.get_assumptions(m_model.get(), asms);
if (m_model.get()) {
validate_assumptions(*m_model.get(), asms);
}
TRACE("qe", tout << asms << "\n";);
solver& s = get_kernel(m_level).s();
lbool res = s.check_sat(asms);
switch (res) {
case l_true:
s.get_model(m_model);
SASSERT(validate_defs("check_sat"));
SASSERT(validate_assumptions(*m_model.get(), asms));
SASSERT(validate_model(asms));
TRACE("qe", s.display(tout); display(tout << "\n", *m_model.get()); display(tout, asms); );
push();
if (m_level == 1 && m_mode == qsat_maximize) {
maximize_model();
}
break;
case l_false:
switch (m_level) {
@ -607,6 +638,7 @@ namespace qe {
return l_true;
}
if (m_model.get()) {
SASSERT(validate_assumptions(*m_model.get(), asms));
if (!project_qe(asms)) return l_undef;
}
else {
@ -734,7 +766,28 @@ namespace qe {
}
}
bool validate_defs(char const* msg) {
if (m_model.get() && !m_pred_abs.validate_defs(*m_model.get())) {
TRACE("qe",
tout << msg << "\n";
display(tout);
if (m_level > 0) {
get_kernel(m_level-1).s().display(tout);
}
expr_ref_vector asms(m);
m_pred_abs.get_assumptions(m_model.get(), asms);
tout << asms << "\n";
m_pred_abs.pred2lit(asms);
tout << asms << "\n";);
return false;
}
else {
return true;
}
}
bool get_core(expr_ref_vector& core, unsigned level) {
SASSERT(validate_defs("get_core"));
get_kernel(level).get_core(core);
m_pred_abs.pred2lit(core);
return true;
@ -814,33 +867,33 @@ namespace qe {
if (!get_core(core, m_level)) {
return false;
}
SASSERT(validate_core(core));
SASSERT(validate_core(mdl, core));
get_vars(m_level);
SASSERT(validate_assumptions(mdl, core));
m_mbp(force_elim(), m_avars, mdl, core);
SASSERT(validate_defs("project_qe"));
if (m_mode == qsat_maximize) {
maximize(core, mdl);
pop(1);
maximize_core(core, mdl);
}
else {
fml = negate_core(core);
add_assumption(fml);
m_answer.push_back(fml);
m_free_vars.append(m_avars);
pop(1);
}
pop(1);
return true;
}
bool project(expr_ref_vector& core) {
if (!get_core(core, m_level)) return false;
TRACE("qe", display(tout); display(tout << "core\n", core););
SASSERT(validate_core(core));
SASSERT(m_level >= 2);
expr_ref fml(m);
expr_ref_vector defs(m), core_save(m);
max_level level;
model& mdl = *m_model.get();
SASSERT(validate_core(mdl, core));
get_vars(m_level-1);
SASSERT(validate_project(mdl, core));
m_mbp(force_elim(), m_avars, mdl, core);
@ -875,6 +928,7 @@ namespace qe {
fml = m_pred_abs.mk_abstract(fml);
get_kernel(m_level).assert_expr(fml);
}
SASSERT(!m_model.get());
return true;
}
@ -1005,7 +1059,19 @@ namespace qe {
}
}
bool validate_core(expr_ref_vector const& core) {
bool validate_assumptions(model& mdl, expr_ref_vector const& core) {
for (unsigned i = 0; i < core.size(); ++i) {
expr_ref val(m);
VERIFY(mdl.eval(core[i], val));
if (!m.is_true(val)) {
TRACE("qe", tout << "component of core is not true: " << mk_pp(core[i], m) << "\n";);
return false;
}
}
return true;
}
bool validate_core(model& mdl, expr_ref_vector const& core) {
return true;
#if 0
TRACE("qe", tout << "Validate core\n";);
@ -1130,7 +1196,8 @@ namespace qe {
m_free_vars(m),
m_objective(0),
m_value(0),
m_was_sat(false)
m_was_sat(false),
m_gt(m)
{
reset();
}
@ -1258,6 +1325,7 @@ namespace qe {
m_objective = t;
m_value = &value;
m_was_sat = false;
m_model_save.reset();
m_pred_abs.abstract_atoms(fml, defs);
fml = m_pred_abs.mk_abstract(fml);
m_ex.assert_expr(mk_and(defs));
@ -1271,6 +1339,7 @@ namespace qe {
if (!m_was_sat) {
return l_false;
}
mdl = m_model_save;
break;
case l_true:
UNREACHABLE();
@ -1286,15 +1355,49 @@ namespace qe {
return l_true;
}
void maximize(expr_ref_vector const& core, model& mdl) {
void maximize_core(expr_ref_vector const& core, model& mdl) {
SASSERT(m_value);
SASSERT(m_objective);
TRACE("qe", tout << "maximize: " << core << "\n";);
m_was_sat |= !core.empty();
expr_ref bound(m);
*m_value = m_mbp.maximize(core, mdl, m_objective, bound);
IF_VERBOSE(0, verbose_stream() << "(maximize " << *m_value << " bound: " << bound << ")\n";);
m_ex.assert_expr(bound);
*m_value = m_value_save;
IF_VERBOSE(3, verbose_stream() << "(maximize " << *m_value << ")\n";);
m_ex.assert_expr(m_gt);
m_fa.assert_expr(m_gt);
}
void maximize_model() {
SASSERT(m_level == 1 && m_mode == qsat_maximize);
SASSERT(m_objective);
expr_ref ge(m);
expr_ref_vector asms(m), defs(m);
m_pred_abs.get_assumptions(m_model.get(), asms);
m_pred_abs.pred2lit(asms);
SASSERT(validate_defs("maximize_model1"));
m_value_save = m_mbp.maximize(asms, *m_model.get(), m_objective, ge, m_gt);
SASSERT(validate_defs("maximize_model2"));
// bound := val <= m_objective
IF_VERBOSE(3, verbose_stream() << "(qsat-maximize-bound: " << m_value_save << ")\n";);
max_level level;
m_pred_abs.abstract_atoms(ge, level, defs);
m_ex.assert_expr(mk_and(defs));
m_fa.assert_expr(mk_and(defs));
ge = m_pred_abs.mk_abstract(ge);
SASSERT(is_uninterp_const(ge));
// update model with evaluation for bound.
if (is_uninterp_const(ge)) {
m_model->register_decl(to_app(ge)->get_decl(), m.mk_true());
}
SASSERT(validate_defs("maximize_model3"));
}
};

2
src/qe/qsat.h
View file

@ -112,6 +112,8 @@ namespace qe {
void display(std::ostream& out) const;
void display(std::ostream& out, expr_ref_vector const& asms) const;
void collect_statistics(statistics& st) const;
bool validate_defs(model& model) const;
};
class qmax {

2
src/smt/smt_context.h
View file

@ -1406,10 +1406,8 @@ namespace smt {
void internalize_instance(expr * body, proof * pr, unsigned generation) {
internalize_assertion(body, pr, generation);
#ifndef SMTCOMP
if (relevancy())
m_case_split_queue->internalize_instance_eh(body, generation);
#endif
}
bool already_internalized() const { return m_e_internalized_stack.size() > 2 || m_b_internalized_stack.size() > 1; }

36
src/smt/smt_model_checker.cpp
View file

@ -138,8 +138,10 @@ namespace smt {
}
bool model_checker::add_instance(quantifier * q, model * cex, expr_ref_vector & sks, bool use_inv) {
if (cex == 0)
return false; // no model available.
if (cex == 0) {
TRACE("model_checker", tout << "no model is available\n";);
return false;
}
unsigned num_decls = q->get_num_decls();
// Remark: sks were created for the flat version of q.
SASSERT(sks.size() >= num_decls);
@ -153,8 +155,10 @@ namespace smt {
sk_value = cex->get_const_interp(sk_d);
if (sk_value == 0) {
sk_value = cex->get_some_value(sk_d->get_range());
if (sk_value == 0)
if (sk_value == 0) {
TRACE("model_checker", tout << "Could not get value for " << sk_d->get_name() << "\n";);
return false; // get_some_value failed... giving up
}
}
if (use_inv) {
unsigned sk_term_gen;
@ -166,6 +170,7 @@ namespace smt {
sk_value = sk_term;
}
else {
TRACE("model_checker", tout << "no inverse value for " << sk_value << "\n";);
return false;
}
}
@ -175,8 +180,10 @@ namespace smt {
sk_value = sk_term;
}
}
if (contains_model_value(sk_value))
if (contains_model_value(sk_value)) {
TRACE("model_checker", tout << "value is private to model: " << sk_value << "\n";);
return false;
}
bindings.set(num_decls - i - 1, sk_value);
}
@ -286,18 +293,15 @@ namespace smt {
break;
model_ref cex;
m_aux_context->get_model(cex);
if (add_instance(q, cex.get(), sks, true)) {
num_new_instances++;
if (num_new_instances < m_max_cexs) {
if (!add_blocking_clause(cex.get(), sks))
break; // add_blocking_clause failed... stop the search for new counter-examples...
}
}
else {
if (!add_instance(q, cex.get(), sks, true)) {
break;
}
if (num_new_instances >= m_max_cexs)
break;
num_new_instances++;
if (num_new_instances >= m_max_cexs || !add_blocking_clause(cex.get(), sks)) {
TRACE("model_checker", tout << "Add blocking clause failed\n";);
// add_blocking_clause failed... stop the search for new counter-examples...
break;
}
}
if (num_new_instances == 0) {
@ -368,8 +372,10 @@ namespace smt {
if (it == end)
return true;
if (m_iteration_idx >= m_params.m_mbqi_max_iterations)
if (m_iteration_idx >= m_params.m_mbqi_max_iterations) {
IF_VERBOSE(10, verbose_stream() << "(smt.mbqi \"max instantiations reached \")" << m_iteration_idx << "\n";);
return false;
}
m_curr_model = md;
m_value2expr.reset();