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fix #3141

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-03-05 07:57:21 +01:00
parent 76d91f7d2b
commit 153d0661fe
3 changed files with 51 additions and 57 deletions
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104
src/model/array_factory.cpp
View file

@ -74,7 +74,7 @@ expr * array_factory::get_some_value(sort * s) {
bool array_factory::mk_two_diff_values_for(sort * s) {
DEBUG_CODE({
value_set * set = 0;
SASSERT(!m_sort2value_set.find(s, set) || set->size() == 0);
SASSERT(!m_sort2value_set.find(s, set) || set->size() <= 1);
});
expr_ref r1(m_manager);
expr_ref r2(m_manager);
@ -91,34 +91,28 @@ bool array_factory::mk_two_diff_values_for(sort * s) {
fi2->insert_entry(args.c_ptr(), r2);
DEBUG_CODE({
value_set * set = 0;
SASSERT(m_sort2value_set.find(s, set) && set->size() == 2);
SASSERT(m_sort2value_set.find(s, set) && set->size() >= 2);
});
return true;
}
bool array_factory::get_some_values(sort * s, expr_ref & v1, expr_ref & v2) {
value_set * set = nullptr;
if (!m_sort2value_set.find(s, set) || set->empty()) {
if (!mk_two_diff_values_for(s))
if (!m_sort2value_set.find(s, set) || set->size() < 2) {
if (!mk_two_diff_values_for(s)) {
TRACE("array_factory_bug", tout << "could not create diff values: " << mk_pp(s, m_manager) << "\n";);
return false;
}
}
m_sort2value_set.find(s, set);
SASSERT(set != 0);
SASSERT(set->size() > 0);
SASSERT(set->size() >= 2);
if (set->size() == 1) {
v1 = *(set->begin());
v2 = get_fresh_value(s);
return v2.get() != nullptr;
}
else {
SASSERT(set->size() >= 2);
value_set::iterator it = set->begin();
v1 = *it;
++it;
v2 = *it;
return true;
}
value_set::iterator it = set->begin();
v1 = *it;
++it;
v2 = *it;
return true;
}
//
@ -144,46 +138,44 @@ expr * array_factory::get_fresh_value(sort * s) {
fi->set_else(range_val);
return val;
}
else {
TRACE("array_factory_bug", tout << "array fresh value: using fresh index, range: " << mk_pp(range, m_manager) << "\n";);
expr_ref v1(m_manager);
expr_ref v2(m_manager);
if (m_model.get_some_values(range, v1, v2)) {
// Claim: A is fresh if A[i1] = v1 and A[i2] = v2 where i1 and i2 are fresh values,
// and v1 and v2 are distinct.
//
// Proof: let assume there is an Array A' such that A' = A.
// Then A[i1] == A'[i1] and A[i2] == A'[i2]. Since, i1 and i2 are fresh,
// A' does not have an entry for i1 or i2, So A'[i1] == A'[i2] == A'.m_else.
// Thus, A[i1] == A[i2] which is a contradiction since v1 != v2 and A[i1] = v1 and A[i2] = v2.
TRACE("array_factory_bug", tout << "v1: " << mk_pp(v1, m_manager) << " v2: " << mk_pp(v2, m_manager) << "\n";);
ptr_buffer<expr> args1;
ptr_buffer<expr> args2;
bool found = false;
unsigned arity = get_array_arity(s);
for (unsigned i = 0; i < arity; i++) {
sort * d = get_array_domain(s, i);
if (!found) {
expr * arg1 = m_model.get_fresh_value(d);
expr * arg2 = m_model.get_fresh_value(d);
if (arg1 != nullptr && arg2 != nullptr) {
found = true;
args1.push_back(arg1);
args2.push_back(arg2);
continue;
}
TRACE("array_factory_bug", tout << "array fresh value: using fresh index, range: " << mk_pp(range, m_manager) << "\n";);
expr_ref v1(m_manager), v2(m_manager), w1(m_manager), w2(m_manager);
if (m_model.get_some_values(range, v1, v2)) {
// Claim: A is fresh if A[i1] = v1 and A[i2] = v2 where i1 and i2 are fresh values,
// and v1 and v2 are distinct.
//
// Proof: let assume there is an Array A' such that A' = A.
// Then A[i1] == A'[i1] and A[i2] == A'[i2]. Since, i1 and i2 are fresh,
// A' does not have an entry for i1 or i2, So A'[i1] == A'[i2] == A'.m_else.
// Thus, A[i1] == A[i2] which is a contradiction since v1 != v2 and A[i1] = v1 and A[i2] = v2.
TRACE("array_factory_bug", tout << "v1: " << mk_pp(v1, m_manager) << " v2: " << mk_pp(v2, m_manager) << "\n";);
ptr_buffer<expr> args1;
ptr_buffer<expr> args2;
bool found = false;
unsigned arity = get_array_arity(s);
for (unsigned i = 0; i < arity; i++) {
sort * d = get_array_domain(s, i);
if (!found) {
expr * arg1 = m_model.get_fresh_value(d);
expr * arg2 = m_model.get_fresh_value(d);
if (arg1 != nullptr && arg2 != nullptr) {
found = true;
args1.push_back(arg1);
args2.push_back(arg2);
continue;
}
expr * arg = m_model.get_some_value(d);
args1.push_back(arg);
args2.push_back(arg);
}
if (found) {
func_interp * fi;
expr * val = mk_array_interp(s, fi);
fi->insert_entry(args1.c_ptr(), v1);
fi->insert_entry(args2.c_ptr(), v2);
return val;
}
expr * arg = m_model.get_some_value(d);
args1.push_back(arg);
args2.push_back(arg);
}
if (found) {
func_interp * fi;
expr * val = mk_array_interp(s, fi);
fi->insert_entry(args1.c_ptr(), v1);
fi->insert_entry(args2.c_ptr(), v2);
return val;
}
}

2
src/smt/smt_model_generator.cpp
View file

@ -318,7 +318,7 @@ namespace smt {
for (source const& curr : sources) {
if (curr.is_fresh_value()) {
sort * s = curr.get_value()->get_sort();
TRACE("model_fresh_bug", tout << curr << " : " << mk_pp(s, m) << "\n";);
TRACE("model_fresh_bug", tout << curr << " : " << mk_pp(s, m) << " " << curr.get_value()->get_value() << "\n";);
expr * val = m_model->get_fresh_value(s);
TRACE("model_fresh_bug", tout << curr << " := #" << (val == nullptr ? UINT_MAX : val->get_id()) << "\n";);
m_asts.push_back(val);

2
src/smt/theory_array_base.cpp
View file

@ -995,6 +995,8 @@ namespace smt {
// IMPORTANT:
// The implementation should not assume a fresh value is created for
// the else_val if the range is finite
TRACE("array", tout << mk_pp(n->get_owner(), get_manager()) << " " << mk_pp(range, get_manager()) << " " << range->is_infinite() << "\n";);
if (range->is_infinite())
else_val = TAG(void*, m.mk_extra_fresh_value(range), 1);
else