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update

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2025-11-14 16:37:00 -08:00
parent d081321384
commit 072f1deccc
1 changed files with 38 additions and 37 deletions
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75
src/math/lp/nla_stellensatz.cpp
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@ -235,8 +235,7 @@ namespace nla {
// otherwise
// find complementary constraints that contain x^k for k = 0 .. degree -1
// eliminate x (and other variables) by combining ci with complementary constraints.
auto ci = m_active.elem_at(0);
auto tabu = m_tabu[ci];
auto ci = m_active.elem_at(0);
m_active.remove(ci);
switch (factor(ci)) {
@ -279,7 +278,7 @@ namespace nla {
continue;
if (p_value < 0 && p_value2 < 0)
continue;
if (any_of(other_ineq.p.free_vars(), [&](unsigned j) { return tabu.contains(j); }))
if (any_of(other_ineq.p.free_vars(), [&](unsigned j) { return m_tabu[ci].contains(j); }))
continue;
TRACE(arith, tout << "factor (" << other_ci << ") " << other_ineq.p << " -> j" << x << "^" << g.degree
@ -317,13 +316,7 @@ namespace nla {
//
lp::constraint_index ci_a, ci_b;
auto aj = assumption_justification();
if (f_p.is_val())
ci_b = multiply(other_ci, pddm.mk_val(f_p.val()));
else if (sign_f)
ci_b = multiply(other_ci, add_constraint(f_p, lp::lconstraint_kind::LT, aj));
else
ci_b = multiply(other_ci, add_constraint(f_p, lp::lconstraint_kind::GT, aj));
if (g_p.is_val())
ci_a = multiply(ci, pddm.mk_val(g_p.val()));
else if (!sign_f)
@ -331,6 +324,13 @@ namespace nla {
else
ci_a = multiply(ci, add_constraint(g_p, lp::lconstraint_kind::GT, aj));
if (f_p.is_val())
ci_b = multiply(other_ci, pddm.mk_val(f_p.val()));
else if (sign_f)
ci_b = multiply(other_ci, add_constraint(f_p, lp::lconstraint_kind::LT, aj));
else
ci_b = multiply(other_ci, add_constraint(f_p, lp::lconstraint_kind::GT, aj));
auto new_ci = add(ci_a, ci_b);
CTRACE(arith, !is_new_constraint(new_ci), display_constraint(tout << "not new ", new_ci) << "\n");
if (!is_new_constraint(new_ci))
@ -351,7 +351,7 @@ namespace nla {
auto const &p = m_constraints[ci].p;
auto const &[new_p, new_k, new_j] = m_constraints[new_ci];
if (new_p.degree() <= 3 && !new_p.free_vars().contains(x)) {
uint_set new_tabu(tabu), fv;
uint_set new_tabu(m_tabu[ci]), fv;
for (auto v : new_p.free_vars())
fv.insert(v);
for (auto v : p.free_vars())
@ -382,34 +382,35 @@ namespace nla {
}
bool stellensatz::vanishing(lpvar x, factorization const &f, lp::constraint_index ci) {
if (f.q.is_zero())
return false;
if (f.p.is_zero())
return false;
auto p_value = cvalue(f.p);
if (!f.p.is_zero() && p_value == 0) {
// add p = 0 as assumption and reduce to q.
auto p_is_0 = assume(f.p, lp::lconstraint_kind::EQ);
if (!f.q.is_zero()) {
// ci & -p_is_0*x^f.degree => new_ci
dd::pdd r = pddm.mk_val(rational(-1));
for (unsigned i = 0; i < f.degree; ++i)
r = r * pddm.mk_var(x);
p_is_0 = multiply(p_is_0, r);
auto new_ci = add(ci, p_is_0);
if (p_value != 0)
return false;
TRACE(arith, display_constraint(tout << "reduced", new_ci) << "\n");
if (!is_new_constraint(new_ci))
return false;
init_occurs(new_ci);
uint_set new_tabu(m_tabu[ci]);
uint_set q_vars;
for (auto j : f.q.free_vars())
q_vars.insert(j);
for (auto j : f.p.free_vars())
if (!q_vars.contains(j))
new_tabu.insert(j);
add_active(new_ci, new_tabu);
}
return true;
}
return false;
// add p = 0 as assumption and reduce to q.
auto p_is_0 = assume(f.p, lp::lconstraint_kind::EQ);
// ci & -p_is_0*x^f.degree => new_ci
dd::pdd r = pddm.mk_val(rational(-1));
for (unsigned i = 0; i < f.degree; ++i)
r = r * pddm.mk_var(x);
p_is_0 = multiply(p_is_0, r);
auto new_ci = add(ci, p_is_0);
TRACE(arith, display_constraint(tout << "reduced", new_ci) << "\n");
if (!is_new_constraint(new_ci))
return false;
init_occurs(new_ci);
uint_set new_tabu(m_tabu[ci]);
uint_set q_vars;
for (auto j : f.q.free_vars())
q_vars.insert(j);
for (auto j : f.p.free_vars())
if (!q_vars.contains(j))
new_tabu.insert(j);
add_active(new_ci, new_tabu);
return true;
}
lbool stellensatz::factor(lp::constraint_index ci) {