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updates

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2025-11-20 10:32:51 -08:00
parent 823800541e
commit fc96f827a1
3 changed files with 60 additions and 18 deletions
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12
src/math/lp/nla_stellensatz.cpp
View file

@ -709,12 +709,9 @@ namespace nla {
while (m_constraints.size() > max_ci) { while (m_constraints.size() > max_ci) {
auto const& [_p, _k, _j] = m_constraints.back(); auto const& [_p, _k, _j] = m_constraints.back();
m_constraint_index.erase({_p.index(), _k}); m_constraint_index.erase({_p.index(), _k});
auto ci = m_constraints.size() - 1;
remove_occurs(ci);
m_constraints.pop_back(); m_constraints.pop_back();
auto ci = m_constraints.size();
if (!m_occurs_trail.empty() && m_occurs_trail.back() == ci) {
remove_occurs(ci);
m_occurs_trail.pop_back();
}
} }
for (auto const &[_p, _k, _j] : replay) { for (auto const &[_p, _k, _j] : replay) {
auto ci = add_constraint(_p, _k, _j); auto ci = add_constraint(_p, _k, _j);
@ -937,13 +934,18 @@ namespace nla {
return; return;
m_occurs_trail.push_back(ci); m_occurs_trail.push_back(ci);
auto const &con = m_constraints[ci]; auto const &con = m_constraints[ci];
verbose_stream() << "init-occurs " << ci << " vars: " << con.p.free_vars() << "\n";
for (auto v : con.p.free_vars()) for (auto v : con.p.free_vars())
m_occurs[v].push_back(ci); m_occurs[v].push_back(ci);
} }
void stellensatz::remove_occurs(lp::constraint_index ci) { void stellensatz::remove_occurs(lp::constraint_index ci) {
if (m_occurs_trail.empty() || m_occurs_trail.back() != ci)
return;
m_occurs_trail.pop_back();
auto const &con = m_constraints[ci]; auto const &con = m_constraints[ci];
verbose_stream() << "remove-occurs " << ci << " vars: " << con.p.free_vars() << "\n";
for (auto v : con.p.free_vars()) for (auto v : con.p.free_vars())
m_occurs[v].pop_back(); m_occurs[v].pop_back();
} }

29
src/math/lp/nra_solver.cpp
View file

@ -161,6 +161,35 @@ struct solver::imp {
} }
} }
void add_tangent_lemmas() {
for (auto const mi : m_nla_core.to_refine()) {
auto const& m = m_nla_core.emon(mi);
if (m.size() != 2)
continue;
auto x = m.vars()[0];
auto y = m.vars()[1];
rational xv = m_nla_core.val(x);
rational yv = m_nla_core.val(y);
rational mv = m_nla_core.val(m.var());
SASSERT(xv * yv != mv);
// a := xv - 1, b := yv - 1
// mv < xv * yv
// (x - a)(y - b) = 1
// (x - a)(y - b) = xy - bx - ay + ab = 1
// mv - bx - ay + ab < 1
// lemma: x > a, y > b => xy - bx - ay + ab >= 1
//
// mv > xv * yv
// a := xv - 1, b := yv + 1
// x > a, y < b => xy - by - ax + ab <= -1
//
// other lemmas around a < x, b < y and a < x, b > y
//
}
}
/** /**
\brief one-shot nlsat check. \brief one-shot nlsat check.
A one shot checker is the least functionality that can A one shot checker is the least functionality that can

37
src/nlsat/nlsat_solver.cpp
View file

@ -1876,6 +1876,7 @@ namespace nlsat {
m_stats.m_conflicts = 0; m_stats.m_conflicts = 0;
m_stats.m_restarts = 0; m_stats.m_restarts = 0;
m_next_conflict = 0; m_next_conflict = 0;
random_gen rand(++m_random_seed);
while (true) { while (true) {
r = search(); r = search();
if (r != l_true) if (r != l_true)
@ -1925,12 +1926,10 @@ namespace nlsat {
// cut on the first model value // cut on the first model value
if (!m_model_values.empty()) { if (!m_model_values.empty()) {
bool found = false; bool found = false;
random_gen r(++m_random_seed);
auto const &[x, value] = bounds[r(bounds.size())]; auto const &[x, value] = bounds[rand(bounds.size())];
for (auto const &[ext_x, mvalue, lo, hi] : m_model_values) { for (auto const &[ext_x, mvalue, lo, hi] : m_model_values) {
if (ext_x == m_perm[x]) { if (ext_x == m_perm[x]) {
verbose_stream() << x << " " << ext_x << " bound: " << mvalue << " value " << value
<< "\n ";
TRACE(nla_solver, tout << "x" << ext_x << " bound " << mvalue << "\n"); TRACE(nla_solver, tout << "x" << ext_x << " bound " << mvalue << "\n");
polynomial_ref p(m_pm); polynomial_ref p(m_pm);
rational one(1); rational one(1);
@ -1955,20 +1954,32 @@ namespace nlsat {
} }
continue; continue;
} }
for (auto const& b : bounds) { for (auto const& [x, lo] : bounds) {
var x = b.first;
rational lo = b.second;
rational hi = lo + 1; // rational::one(); rational hi = lo + 1; // rational::one();
bool is_even = false; bool is_even = false;
polynomial_ref p(m_pm); polynomial_ref p(m_pm);
rational one(1); rational one(1);
m_lemma.reset(); m_lemma.reset();
p = m_pm.mk_linear(1, &one, &x, -lo); auto add_gt = [&]() {
poly* p1 = p.get(); p = m_pm.mk_linear(1, &one, &x, -lo);
m_lemma.push_back(~mk_ineq_literal(atom::GT, 1, &p1, &is_even)); poly *p1 = p.get();
p = m_pm.mk_linear(1, &one, &x, -hi); m_lemma.push_back(~mk_ineq_literal(atom::GT, 1, &p1, &is_even));
poly* p2 = p.get(); };
m_lemma.push_back(~mk_ineq_literal(atom::LT, 1, &p2, &is_even)); auto add_lt = [&]() {
p = m_pm.mk_linear(1, &one, &x, -hi);
poly *p2 = p.get();
m_lemma.push_back(~mk_ineq_literal(atom::LT, 1, &p2, &is_even));
};
if (rand(2) == 0) {
add_gt();
add_lt();
}
else {
add_lt();
add_gt();
}
// perform branch and bound // perform branch and bound
clause * cls = mk_clause(m_lemma.size(), m_lemma.data(), true, nullptr); clause * cls = mk_clause(m_lemma.size(), m_lemma.data(), true, nullptr);