mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2026-04-27 14:23:35 +00:00
Code Activity

fixing cause of divergence

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2025-12-03 16:37:45 -08:00
parent f352cc6393
commit 21dc38048f
2 changed files with 25 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

25
src/math/lp/nla_stellensatz.cpp
View file

@ -473,7 +473,7 @@ namespace nla {
++level; ++level;
else if (conflict(ci)) else if (conflict(ci))
return l_false; return l_false;
else if (m_processed.contains(ci)) else if (m_processed.contains(ci) || constraint_is_trivial(ci))
++level; ++level;
else else
level = max_level(m_constraints[ci]); level = max_level(m_constraints[ci]);
@ -559,17 +559,21 @@ namespace nla {
CTRACE(arith_verbose, !m_active.contains(ci), display_constraint(tout << "skip inactive ", ci) << "\n"); CTRACE(arith_verbose, !m_active.contains(ci), display_constraint(tout << "skip inactive ", ci) << "\n");
if (!m_active.contains(ci)) if (!m_active.contains(ci))
continue; continue;
m_processed.insert(ci);
// consider only constraints where v is maximal // consider only constraints where v is maximal
auto const &p = m_constraints[ci].p; auto const &p = m_constraints[ci].p;
auto const &vars = p.free_vars(); auto const &vars = p.free_vars();
if (any_of(vars, [&](unsigned j) { return p.degree(j) == 1 && m_var2level[j] > m_var2level[v]; })) { if (any_of(vars, [&](unsigned j) { return p.degree(j) == 1 && m_var2level[j] > m_var2level[v]; })) {
m_processed.insert(ci);
TRACE(arith_verbose, display_constraint(tout << "skip non-maximal ", ci) << "\n"); TRACE(arith_verbose, display_constraint(tout << "skip non-maximal ", ci) << "\n");
continue; continue;
} }
auto f = factor(v, ci); auto f = factor(v, ci);
auto q_ge_0 = vanishing(v, f, ci); auto q_ge_0 = vanishing(v, f, ci);
if (q_ge_0 != lp::null_ci) { if (q_ge_0 != lp::null_ci) {
if (m_processed.contains(ci))
continue;
m_processed.insert(ci);
if (!constraint_is_true(q_ge_0)) { if (!constraint_is_true(q_ge_0)) {
van = q_ge_0; van = q_ge_0;
return result; return result;
@ -578,6 +582,7 @@ namespace nla {
display_constraint(tout << " to ", q_ge_0) << "\n";); display_constraint(tout << " to ", q_ge_0) << "\n";);
continue; continue;
} }
m_processed.insert(ci);
if (f.degree > 1) if (f.degree > 1)
continue; continue;
TRACE(arith_verbose, display_constraint(tout << "process maximal ", ci) << "\n"); TRACE(arith_verbose, display_constraint(tout << "process maximal ", ci) << "\n");
@ -1022,6 +1027,22 @@ namespace nla {
} }
} }
bool stellensatz::constraint_is_trivial(lp::constraint_index ci) const {
return ci != lp::null_ci && constraint_is_trivial(m_constraints[ci]);
}
bool stellensatz::constraint_is_trivial(constraint const &c) const {
auto const &[p, k, j] = c;
if (!p.is_val())
return false;
if (p.val() > 0)
return k == lp::lconstraint_kind::GE || k == lp::lconstraint_kind::GT || k == lp::lconstraint_kind::NE;
else if (p.val() == 0)
return k == lp::lconstraint_kind::EQ || k == lp::lconstraint_kind::GE || k == lp::lconstraint_kind::LE;
else // p.val() < 0
return k == lp::lconstraint_kind::LE || k == lp::lconstraint_kind::LT || k == lp::lconstraint_kind::NE;
}
bool stellensatz::constraint_is_conflict(lp::constraint_index ci) const { bool stellensatz::constraint_is_conflict(lp::constraint_index ci) const {
return ci != lp::null_ci && constraint_is_conflict(m_constraints[ci]); return ci != lp::null_ci && constraint_is_conflict(m_constraints[ci]);
} }

2
src/math/lp/nla_stellensatz.h
View file

@ -209,6 +209,8 @@ namespace nla {
bool constraint_is_true(constraint const &c) const; bool constraint_is_true(constraint const &c) const;
bool constraint_is_conflict(lp::constraint_index ci) const; bool constraint_is_conflict(lp::constraint_index ci) const;
bool constraint_is_conflict(constraint const &c) const; bool constraint_is_conflict(constraint const &c) const;
bool constraint_is_trivial(lp::constraint_index ci) const;
bool constraint_is_trivial(constraint const& c) const;
bool is_new_constraint(lp::constraint_index ci) const; bool is_new_constraint(lp::constraint_index ci) const;
lp::constraint_index gcd_normalize(lp::constraint_index ci); lp::constraint_index gcd_normalize(lp::constraint_index ci);