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Merge branch 'master' of https://github.com/z3prover/z3

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This commit is contained in:
Nikolaj Bjorner 2019-01-25 20:30:19 -08:00
parent 4fb729a7d2 e7cabf3e44
commit f781e93774
4 changed files with 78 additions and 30 deletions
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10
src/api/python/z3/z3.py
View file

@ -5340,7 +5340,7 @@ class Goal(Z3PPObject):
def __copy__(self):
return self.translate(self.ctx)
def __deepcopy__(self):
def __deepcopy__(self, memo={}):
return self.translate(self.ctx)
def simplify(self, *arguments, **keywords):
@ -5528,7 +5528,7 @@ class AstVector(Z3PPObject):
def __copy__(self):
return self.translate(self.ctx)
def __deepcopy__(self):
def __deepcopy__(self, memo={}):
return self.translate(self.ctx)
def __repr__(self):
@ -5872,7 +5872,7 @@ class FuncInterp(Z3PPObject):
def __copy__(self):
return self.translate(self.ctx)
def __deepcopy__(self):
def __deepcopy__(self, memo={}):
return self.translate(self.ctx)
def as_list(self):
@ -6168,7 +6168,7 @@ class ModelRef(Z3PPObject):
def __copy__(self):
return self.translate(self.ctx)
def __deepcopy__(self):
def __deepcopy__(self, memo={}):
return self.translate(self.ctx)
def Model(ctx = None):
@ -6786,7 +6786,7 @@ class Solver(Z3PPObject):
def __copy__(self):
return self.translate(self.ctx)
def __deepcopy__(self):
def __deepcopy__(self, memo={}):
return self.translate(self.ctx)
def sexpr(self):

94
src/opt/maxlex.cpp
View file

@ -26,10 +26,6 @@ Author:
namespace opt {
bool is_maxlex(weights_t & _ws) {
// disable for now
#if true
return false;
#else
vector<rational> ws(_ws);
std::sort(ws.begin(), ws.end());
ws.reverse();
@ -42,7 +38,6 @@ namespace opt {
sum -= w;
}
return true;
#endif
}
class maxlex : public maxsmt_solver_base {
@ -85,21 +80,23 @@ namespace opt {
}
void update_assignment(model_ref & mdl) {
bool prefix_defined = true;
bool first_undef = true, second_undef = false;
for (auto & soft : m_soft) {
if (!prefix_defined) {
set_value(soft, l_undef);
if (first_undef && soft.value != l_undef) {
continue;
}
switch (soft.value) {
case l_undef:
prefix_defined = mdl->is_true(soft.s);
set_value(soft, prefix_defined ? l_true : l_undef);
break;
case l_true:
break;
case l_false:
break;
first_undef = false;
if (soft.value != l_false) {
lbool v = mdl->is_true(soft.s) ? l_true : l_undef;;
if (v == l_undef) {
second_undef = true;
}
if (second_undef) {
soft.set_value(v);
}
else {
set_value(soft, v); // also update constraints
}
}
}
update_bounds();
@ -108,15 +105,9 @@ namespace opt {
void update_bounds() {
m_lower.reset();
m_upper.reset();
bool prefix_defined = true;
for (auto & soft : m_soft) {
if (!prefix_defined) {
m_upper += soft.weight;
continue;
}
switch (soft.value) {
case l_undef:
prefix_defined = false;
m_upper += soft.weight;
break;
case l_true:
@ -131,6 +122,9 @@ namespace opt {
}
void init() {
for (auto & soft : m_soft) {
soft.set_value(l_undef);
}
model_ref mdl;
s().get_model(mdl);
update_assignment(mdl);
@ -216,9 +210,20 @@ namespace opt {
// a, b is unsat, a, not b is unsat -> a is unsat
// b is unsat, a, not b is unsat -> not a, not b
set_value(soft, l_false);
// core1 = { b }
// core2 = { a, not b }
if (!core.contains(a)) {
set_value(soft2, l_false);
}
else {
// core1 = { a, b}
// core2 = { not_b }
core.reset();
s().get_unsat_core(core);
if (!core.contains(a)) {
set_value(soft2, l_true);
}
}
update_bounds();
break;
case l_undef:
@ -238,6 +243,47 @@ namespace opt {
return l_true;
}
// every time probing whether to include soft_i,
// include suffix that is known to be assignable to T
lbool maxlexN() {
unsigned sz = m_soft.size();
for (unsigned i = 0; i < sz; ++i) {
auto& soft = m_soft[i];
if (soft.value != l_undef) {
continue;
}
expr_ref_vector asms(m);
asms.push_back(soft.s);
for (unsigned j = i + 1; j < sz; ++j) {
auto& soft2 = m_soft[j];
if (soft2.value == l_true) {
asms.push_back(soft2.s);
}
}
lbool is_sat = s().check_sat(asms);
switch (is_sat) {
case l_true:
update_assignment();
SASSERT(soft.value == l_true);
break;
case l_false:
set_value(soft, l_false);
for (unsigned j = i + 1; j < sz; ++j) {
auto& soft2 = m_soft[j];
if (soft2.value != l_true) {
break;
}
assert_value(soft2);
}
update_bounds();
break;
case l_undef:
return l_undef;
}
}
return l_true;
}
public:
maxlex(maxsat_context& c, unsigned id, weights_t & ws, expr_ref_vector const& s):
@ -251,7 +297,7 @@ namespace opt {
lbool operator()() override {
init();
return maxlex1();
return maxlexN();
}

3
src/opt/maxsmt.cpp
View file

@ -232,10 +232,11 @@ namespace opt {
lbool maxsmt::operator()() {
lbool is_sat = l_undef;
m_msolver = nullptr;
opt_params optp(m_params);
symbol const& maxsat_engine = m_c.maxsat_engine();
IF_VERBOSE(1, verbose_stream() << "(maxsmt)\n";);
TRACE("opt_verbose", s().display(tout << "maxsmt\n") << "\n";);
if (is_maxlex(m_weights)) {
if (optp.maxlex_enable() && is_maxlex(m_weights)) {
m_msolver = mk_maxlex(m_c, m_index, m_weights, m_soft_constraints);
}
else if (m_soft_constraints.empty() || maxsat_engine == symbol("maxres") || maxsat_engine == symbol::null) {

1
src/opt/opt_params.pyg
View file

@ -14,6 +14,7 @@ def_module_params('opt',
('elim_01', BOOL, True, 'eliminate 01 variables'),
('pp.neat', BOOL, True, 'use neat (as opposed to less readable, but faster) pretty printer when displaying context'),
('pb.compile_equality', BOOL, False, 'compile arithmetical equalities into pseudo-Boolean equality (instead of two inequalites)'),
('maxlex.enable', BOOL, False, 'enable maxlex heuristic for lexicographic MaxSAT problems'),
('maxres.hill_climb', BOOL, True, 'give preference for large weight cores'),
('maxres.add_upper_bound_block', BOOL, False, 'restict upper bound with constraint'),
('maxres.max_num_cores', UINT, UINT_MAX, 'maximal number of cores per round'),