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fix #7027

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TODO: review old nlsat bugs for effect of this fix.
This commit is contained in:
Nikolaj Bjorner 2024-01-23 14:56:15 -08:00
parent 125a82bea5
commit be7856c57d
4 changed files with 117 additions and 53 deletions
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51
src/nlsat/nlsat_explain.cpp
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@ -38,7 +38,7 @@ namespace nlsat {
polynomial_ref_vector m_ps;
polynomial_ref_vector m_ps2;
polynomial_ref_vector m_psc_tmp;
polynomial_ref_vector m_factors;
polynomial_ref_vector m_factors, m_factors_save;
scoped_anum_vector m_roots_tmp;
bool m_simplify_cores;
bool m_full_dimensional;
@ -142,6 +142,7 @@ namespace nlsat {
m_ps2(m_pm),
m_psc_tmp(m_pm),
m_factors(m_pm),
m_factors_save(m_pm),
m_roots_tmp(m_am),
m_todo(u),
m_core1(s),
@ -259,22 +260,42 @@ namespace nlsat {
*/
ptr_vector<poly> m_zero_fs;
bool_vector m_is_even;
struct restore_factors {
polynomial_ref_vector& m_factors, &m_factors_save;
unsigned num_saved = 0;
restore_factors(polynomial_ref_vector&f, polynomial_ref_vector& fs):
m_factors(f), m_factors_save(fs)
{
num_saved = m_factors_save.size();
m_factors_save.append(m_factors);
}
~restore_factors() {
m_factors.reset();
m_factors.append(m_factors_save.size() - num_saved, m_factors_save.data() + num_saved);
m_factors_save.shrink(num_saved);
}
};
void add_zero_assumption(polynomial_ref & p) {
// If p is of the form p1^n1 * ... * pk^nk,
// then only the factors that are zero in the current interpretation needed to be considered.
// I don't want to create a nested conjunction in the clause.
// Then, I assert p_i1 * ... * p_im != 0
factor(p, m_factors);
unsigned num_factors = m_factors.size();
m_zero_fs.reset();
m_is_even.reset();
polynomial_ref f(m_pm);
for (unsigned i = 0; i < num_factors; i++) {
f = m_factors.get(i);
if (is_zero(sign(f))) {
m_zero_fs.push_back(m_factors.get(i));
m_is_even.push_back(false);
}
{
restore_factors _restore(m_factors, m_factors_save);
factor(p, m_factors);
unsigned num_factors = m_factors.size();
m_zero_fs.reset();
m_is_even.reset();
polynomial_ref f(m_pm);
for (unsigned i = 0; i < num_factors; i++) {
f = m_factors.get(i);
if (is_zero(sign(f))) {
m_zero_fs.push_back(m_factors.get(i));
m_is_even.push_back(false);
}
}
}
SASSERT(!m_zero_fs.empty()); // one of the factors must be zero in the current interpretation, since p is zero in it.
literal l = m_solver.mk_ineq_literal(atom::EQ, m_zero_fs.size(), m_zero_fs.data(), m_is_even.data());
@ -582,8 +603,9 @@ namespace nlsat {
if (is_const(p))
return;
if (m_factor) {
TRACE("nlsat_explain", display(tout << "adding factors of\n", p); tout << "\n";);
restore_factors _restore(m_factors, m_factors_save);
factor(p, m_factors);
TRACE("nlsat_explain", display(tout << "adding factors of\n", p); tout << "\n" << m_factors << "\n";);
polynomial_ref f(m_pm);
for (unsigned i = 0; i < m_factors.size(); i++) {
f = m_factors.get(i);
@ -859,6 +881,7 @@ namespace nlsat {
*/
void mk_linear_root(atom::kind k, var y, unsigned i, poly * p, bool mk_neg) {
TRACE("nlsat_explain", display_var(tout, y); m_pm.display(tout << ": ", p, m_solver.display_proc()); tout << "\n");
polynomial_ref p_prime(m_pm);
p_prime = p;
bool lsign = false;
@ -1379,7 +1402,7 @@ namespace nlsat {
var max_x = max_var(m_ps);
TRACE("nlsat_explain", tout << "polynomials in the conflict:\n"; display(tout, m_ps); tout << "\n";);
elim_vanishing(m_ps);
TRACE("nlsat_explain", tout << "elim vanishing\n"; display(tout, m_ps); tout << "\n";);
TRACE("nlsat_explain", tout << "elim vanishing x" << max_x << "\n"; display(tout, m_ps); tout << "\n";);
project(m_ps, max_x);
TRACE("nlsat_explain", tout << "after projection\n"; display(tout, m_ps); tout << "\n";);
}