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add toggle to use polynomial translation

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2025-11-17 17:28:28 -08:00
parent 2eca05e59a
commit 33709d3abb
3 changed files with 127 additions and 17 deletions
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14
src/math/lp/nla_stellensatz.cpp
View file

@ -224,6 +224,7 @@ namespace nla {
if (m_active.contains(ci))
return;
m_active.insert(ci);
m_tabu.reserve(ci + 1);
m_tabu[ci] = tabu;
}
@ -544,7 +545,7 @@ namespace nla {
lbool stellensatz::factor(lp::constraint_index ci) {
auto const &[p, k, j] = m_constraints[ci];
auto [vars, q] = p.var_factors();
auto [vars, q] = p.var_factors(); // p = vars * q
auto add_new = [&](lp::constraint_index new_ci) {
SASSERT(!constraint_is_true(new_ci));
@ -567,7 +568,7 @@ namespace nla {
};
TRACE(arith, tout << "factor (" << ci << ") " << p << " q: " << q << " vars: " << vars << "\n");
if (vars.empty()) {
if (false && vars.empty()) {
for (auto v : p.free_vars()) {
if (value(v) == 0)
return subst(v, pddm.mk_val(0));
@ -577,10 +578,13 @@ namespace nla {
return subst(v, pddm.mk_val(rational(-1)));
}
return l_undef;
}
}
if (vars.empty())
return l_undef;
for (auto v : vars) {
if (value(v) == 0)
return subst(v, pddm.mk_val(0));
return l_undef;
// return subst(v, pddm.mk_val(0));
}
vector<dd::pdd> muls;
muls.push_back(q);
@ -661,7 +665,7 @@ namespace nla {
explain_constraint(new_lemma, m.ci, ex);
}
else if (std::holds_alternative<assumption_justification>(b)) {
auto [t, coeff] = to_term_offset(p);
auto [t, coeff] = to_term_offset(p);
new_lemma |= ineq(t, negate(k), -coeff);
}
else if (std::holds_alternative<gcd_justification>(b)) {

129
src/math/lp/nra_solver.cpp
View file

@ -57,6 +57,99 @@ struct solver::imp {
m_lp2nl.reset();
}
struct eq {
bool operator()(unsigned_vector const &a, unsigned_vector const &b) const {
return a == b;
}
};
map<unsigned_vector, unsigned, svector_hash<unsigned_hash>, eq> m_vars2mon;
// Create polynomial definition for variable v used in setup_assignment_solver.
// Side-effects: updates m_vars2mon when v is a monic variable.
void mk_definition(unsigned v, polynomial_ref_vector &definitions) {
auto &pm = m_nlsat->pm();
polynomial::polynomial_ref p(pm);
if (m_nla_core.emons().is_monic_var(v)) {
auto const &m = m_nla_core.emons()[v];
auto vars = m.vars();
std::sort(vars.begin(), vars.end());
m_vars2mon.insert(vars, v);
for (auto v2 : vars) {
auto pv = definitions.get(v2);
if (!p)
p = pv;
else
p = pm.mul(p, pv);
}
}
else if (lra.column_has_term(v)) {
for (auto const &[w, coeff] : lra.get_term(v)) {
auto pw = definitions.get(w);
if (!p)
p = pm.mul(coeff, pw);
else
p = pm.add(p, pm.mul(coeff, pw));
}
}
else {
p = pm.mk_polynomial(v); // nlsat var index equals v (verified above when created)
}
definitions.push_back(p);
}
void setup_solver_poly() {
m_vars2mon.reset();
m_coi.init();
auto &pm = m_nlsat->pm();
polynomial_ref_vector definitions(pm);
for (unsigned v = 0; v < lra.number_of_vars(); ++v) {
auto j = m_nlsat->mk_var(lra.var_is_int(v));
VERIFY(j == v);
m_lp2nl.insert(v, j); // we don't really need this. It is going to be the identify map.
scoped_anum a(am());
am().set(a, m_nla_core.val(v).to_mpq());
m_values->push_back(a);
mk_definition(v, definitions);
}
// we rely on that all information encoded into the tableau is present as a constraint.
for (auto ci : m_coi.constraints()) {
auto &c = lra.constraints()[ci];
auto &pm = m_nlsat->pm();
auto k = c.kind();
auto rhs = c.rhs();
auto lhs = c.coeffs();
rational den = denominator(rhs);
for (auto [coeff, v] : lhs)
den = lcm(den, denominator(coeff));
polynomial::polynomial_ref p(pm);
p = pm.mk_const(-den * rhs);
for (auto [coeff, v] : lhs) {
polynomial_ref poly(pm);
poly = pm.mul(den * coeff, definitions.get(v));
p = p + poly;
}
auto lit = add_constraint(p, ci, k);
}
}
void setup_solver_terms() {
m_coi.init();
// add linear inequalities from lra_solver
for (auto ci : m_coi.constraints())
add_constraint(ci);
// add polynomial definitions.
for (auto const &m : m_coi.mons())
add_monic_eq(m_nla_core.emons()[m]);
// add term definitions.
for (unsigned i : m_coi.terms())
add_term(i);
}
/**
\brief one-shot nlsat check.
A one shot checker is the least functionality that can
@ -73,22 +166,17 @@ struct solver::imp {
reset();
vector<nlsat::assumption, false> core;
m_coi.init();
// add linear inequalities from lra_solver
for (auto ci : m_coi.constraints())
add_constraint(ci);
// add polynomial definitions.
for (auto const& m : m_coi.mons())
add_monic_eq(m_nla_core.emons()[m]);
// add term definitions.
for (unsigned i : m_coi.terms())
add_term(i);
smt_params_helper p(m_params);
if (p.arith_nl_nra_poly())
setup_solver_poly();
else
setup_solver_terms();
TRACE(nra, m_nlsat->display(tout));
smt_params_helper p(m_params);
if (p.arith_nl_log()) {
static unsigned id = 0;
std::stringstream strm;
@ -248,6 +336,23 @@ struct solver::imp {
m_nlsat->mk_clause(1, &lit, a);
}
nlsat::literal add_constraint(polynomial::polynomial *p, unsigned idx, lp::lconstraint_kind k) {
polynomial::polynomial *ps[1] = {p};
bool is_even[1] = {false};
nlsat::literal lit;
nlsat::assumption a = this + idx;
switch (k) {
case lp::lconstraint_kind::LE: lit = ~m_nlsat->mk_ineq_literal(nlsat::atom::kind::GT, 1, ps, is_even); break;
case lp::lconstraint_kind::GE: lit = ~m_nlsat->mk_ineq_literal(nlsat::atom::kind::LT, 1, ps, is_even); break;
case lp::lconstraint_kind::LT: lit = m_nlsat->mk_ineq_literal(nlsat::atom::kind::LT, 1, ps, is_even); break;
case lp::lconstraint_kind::GT: lit = m_nlsat->mk_ineq_literal(nlsat::atom::kind::GT, 1, ps, is_even); break;
case lp::lconstraint_kind::EQ: lit = m_nlsat->mk_ineq_literal(nlsat::atom::kind::EQ, 1, ps, is_even); break;
default: UNREACHABLE(); // unreachable
}
m_nlsat->mk_clause(1, &lit, a);
return lit;
}
bool check_monic(mon_eq const& m) {
scoped_anum val1(am()), val2(am());
am().set(val1, value(m.var()));

1
src/params/smt_params_helper.pyg
View file

@ -91,6 +91,7 @@ def_module_params(module_name='smt',
('arith.nl.cross_nested', BOOL, True, 'enable cross-nested consistency checking'),
('arith.nl.stellensatz', BOOL, False, 'enable stellensatz saturation'),
('arith.nl.linearize', BOOL, True, 'enable NL linearization'),
('arith.nl.nra.poly', BOOL, False, 'use polynomial translation'),
('arith.nl.log', BOOL, False, 'Log lemmas sent to nra solver'),
('arith.propagate_eqs', BOOL, True, 'propagate (cheap) equalities'),
('arith.epsilon', DOUBLE, 1.0, 'initial value of epsilon used for model generation of infinitesimals'),