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fix #2613 fix #2612

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-10-05 16:57:51 -07:00
parent 016732aa59
commit 39edf73e78
16 changed files with 222 additions and 162 deletions
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50
src/nlsat/nlsat_explain.cpp
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@ -197,9 +197,10 @@ namespace nlsat {
\brief Reset m_already_added vector using m_result
*/
void reset_already_added() {
SASSERT(m_result != 0);
SASSERT(m_result != nullptr);
for (literal lit : *m_result)
m_already_added_literal[lit.index()] = false;
SASSERT(check_already_added());
}
@ -207,9 +208,9 @@ namespace nlsat {
\brief evaluate the given polynomial in the current interpretation.
max_var(p) must be assigned in the current interpretation.
*/
int sign(polynomial_ref const & p) {
polynomial::sign sign(polynomial_ref const & p) {
SASSERT(max_var(p) == null_var || m_assignment.is_assigned(max_var(p)));
int s = m_am.eval_sign_at(p, m_assignment);
auto s = m_am.eval_sign_at(p, m_assignment);
TRACE("nlsat_explain", tout << "p: " << p << " var: " << max_var(p) << " sign: " << s << "\n";);
return s;
}
@ -270,7 +271,7 @@ namespace nlsat {
polynomial_ref f(m_pm);
for (unsigned i = 0; i < num_factors; i++) {
f = m_factors.get(i);
if (sign(f) == 0) {
if (sign(f) == polynomial::sign_zero) {
m_zero_fs.push_back(m_factors.get(i));
m_is_even.push_back(false);
}
@ -323,7 +324,7 @@ namespace nlsat {
return; // lc is a nonzero constant
lc = m_pm.coeff(p, x, k, reduct);
if (!is_zero(lc)) {
if (sign(lc) != 0)
if (sign(lc) != polynomial::sign_zero)
return;
// lc is not the zero polynomial, but it vanished in the current interpretation.
// so we keep searching...
@ -959,8 +960,9 @@ namespace nlsat {
if (ps.empty())
return;
m_todo.reset();
for (unsigned i = 0; i < ps.size(); i++)
m_todo.insert(ps.get(i));
for (poly* p : ps) {
m_todo.insert(p);
}
var x = m_todo.remove_max_polys(ps);
// Remark: after vanishing coefficients are eliminated, ps may not contain max_x anymore
if (x < max_x)
@ -983,8 +985,8 @@ namespace nlsat {
}
bool check_already_added() const {
for (unsigned i = 0; i < m_already_added_literal.size(); i++) {
SASSERT(m_already_added_literal[i] == false);
for (bool b : m_already_added_literal) {
SASSERT(!b);
}
return true;
}
@ -1062,7 +1064,7 @@ namespace nlsat {
void simplify(literal l, eq_info & info, var max, scoped_literal & new_lit) {
bool_var b = l.var();
atom * a = m_atoms[b];
SASSERT(a != 0);
SASSERT(a);
if (a->is_root_atom()) {
new_lit = l;
return;
@ -1091,19 +1093,24 @@ namespace nlsat {
modified_lit = true;
unsigned d;
m_pm.pseudo_remainder(f, info.m_eq, info.m_x, d, new_factor);
polynomial_ref fact(f, m_pm), eq(const_cast<poly*>(info.m_eq), m_pm);
TRACE("nlsat_simplify_core", tout << "d: " << d << " factor " << fact << " eq " << eq << " new factor " << new_factor << "\n";);
// adjust sign based on sign of lc of eq
if (d % 2 == 1 && // d is odd
!is_even && // degree of the factor is odd
info.m_lc_sign < 0 // lc of the eq is negative
) {
if (d % 2 == 1 && // d is odd
!is_even && // degree of the factor is odd
info.m_lc_sign < 0) { // lc of the eq is negative
atom_sign = -atom_sign; // flipped the sign of the current literal
TRACE("nlsat_simplify_core", tout << "odd degree\n";);
}
if (is_const(new_factor)) {
int s = sign(new_factor);
if (s == 0) {
TRACE("nlsat_simplify_core", tout << "new factor is const\n";);
polynomial::sign s = sign(new_factor);
if (s == polynomial::sign_zero) {
bool atom_val = a->get_kind() == atom::EQ;
bool lit_val = l.sign() ? !atom_val : atom_val;
new_lit = lit_val ? true_literal : false_literal;
TRACE("nlsat_simplify_core", tout << "zero sign: " << info.m_lc_const << "\n";);
if (!info.m_lc_const) {
// We have essentially shown the current factor must be zero If the leading coefficient is not zero.
// Note that, if the current factor is zero, then the whole polynomial is zero.
@ -1115,6 +1122,7 @@ namespace nlsat {
return;
}
else {
TRACE("nlsat_simplify_core", tout << "non-zero sign: " << info.m_lc_const << "\n";);
// We have shown the current factor is a constant MODULO the sign of the leading coefficient (of the equation used to rewrite the factor).
if (!info.m_lc_const) {
// If the leading coefficient is not a constant, we must store this information as an extra assumption.
@ -1266,11 +1274,9 @@ namespace nlsat {
var_vector m_select_tmp;
ineq_atom * select_lower_stage_eq(scoped_literal_vector & C, var max) {
var_vector & xs = m_select_tmp;
unsigned sz = C.size();
for (unsigned i = 0; i < sz; i++) {
literal l = C[i];
for (literal l : C) {
bool_var b = l.var();
atom * a = m_atoms[b];
atom * a = m_atoms[b];
if (a->is_root_atom())
continue; // we don't rewrite root atoms
ineq_atom * _a = to_ineq_atom(a);
@ -1279,9 +1285,7 @@ namespace nlsat {
poly * p = _a->p(j);
xs.reset();
m_pm.vars(p, xs);
unsigned xs_sz = xs.size();
for (unsigned k = 0; k < xs_sz; k++) {
var y = xs[k];
for (var y : xs) {
if (y >= max)
continue;
atom * eq = m_x2eq[y];