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sketch fixed variable callback mechanism

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This commit is contained in:
Nikolaj Bjorner 2025-01-08 12:50:46 -08:00
parent c1a62d346c
commit 270c127407
3 changed files with 63 additions and 2 deletions
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8
src/math/lp/lar_solver.cpp
View file

@ -1950,14 +1950,20 @@ namespace lp {
tout << std::endl;
}
});
bool was_fixed = column_is_fixed(j);
mpq rs = adjust_bound_for_int(j, kind, right_side);
if (column_has_upper_bound(j))
update_column_type_and_bound_with_ub(j, kind, rs, dep);
else
update_column_type_and_bound_with_no_ub(j, kind, rs, dep);
if (is_base(j) && column_is_fixed(j))
if (!was_fixed && column_is_fixed(j) && m_fixed_var_eh)
m_fixed_var_eh(j);
if (is_base(j) && column_is_fixed(j))
m_fixed_base_var_set.insert(j);
TRACE("lar_solver_feas", tout << "j = " << j << " became " << (this->column_is_feasible(j) ? "feas" : "non-feas") << ", and " << (this->column_is_bounded(j) ? "bounded" : "non-bounded") << std::endl;);
}

1
src/math/lp/lar_solver.h
View file

@ -311,6 +311,7 @@ public:
inline void restore_x() { m_mpq_lar_core_solver.m_r_x = m_backup_x; }
std::function<void(lpvar)> m_fixed_var_eh;
template <typename T>
void explain_implied_bound(const implied_bound& ib, lp_bound_propagator<T>& bp) {
u_dependency* dep = ib.explain_implied();

56
src/smt/theory_lra.cpp
View file

@ -254,6 +254,47 @@ class theory_lra::imp {
return add_const(0, is_int ? m_zero_var : m_rzero_var, is_int);
}
svector<theory_var> m_fixed_vars;
unsigned m_fixed_vars_head = 0;
bool propagate_fixed_vars() {
if (m_fixed_vars_head == m_fixed_vars.size())
return false;
ctx().push_trail(value_trail(m_fixed_vars_head));
bool propagated = false;
while (m_fixed_vars_head < m_fixed_vars.size()) {
theory_var v = m_fixed_vars[m_fixed_vars_head++];
enode* n = th.get_enode(v);
for (enode* p : n->get_parents()) {
expr* e = p->get_expr();
expr* x, * y;
if (!a.is_mul(e, x, y))
continue;
if (a.is_numeral(x) || a.is_numeral(y))
continue;
if (x == n->get_expr()) {
std::swap(x, y);
}
if (y != n->get_expr())
continue;
// comment out to enable propagation:
continue;
expr_ref k(a.mk_numeral(get_value(v), a.is_int(y)), m);
expr_ref eq(a.mk_eq(y, k), m);
literal eq1 = th.mk_eq(y, k, false);
literal eq2 = th.mk_eq(e, a.mk_mul(x, k), false);
ctx().mk_th_axiom(get_id(), ~eq1, eq2);
// v2 could perform propagation directly
// v3 could consider multiplication of more than two variables.
// such as e := x * y * z. If both x, y become fixed we have e = z * value(x) * value(y)
// verbose_stream() << mk_bounded_pp(e, m) << " - " << mk_bounded_pp(n->get_expr(), m) << "\n";
}
}
return propagated;
}
void ensure_nla() {
if (!m_nla) {
m_nla = alloc(nla::solver, *m_solver.get(), ctx().get_params(), m.limit());
@ -266,6 +307,7 @@ class theory_lra::imp {
return ctx().is_relevant(th.get_enode(u));
};
m_nla->set_relevant(is_relevant);
}
}
@ -873,6 +915,18 @@ public:
lp().settings().int_run_gcd_test() = ctx().get_fparams().m_arith_gcd_test;
lp().settings().set_random_seed(ctx().get_fparams().m_random_seed);
m_lia = alloc(lp::int_solver, *m_solver.get());
std::function<void(lpvar)> new_fixed = [&](lpvar v) {
theory_var u = lp().local_to_external(v);
if (u == null_theory_var)
return;
expr* var = th.get_expr(u);
if (a.is_numeral(var))
return;
m_fixed_vars.push_back(u);
ctx().push_trail(push_back_vector(m_fixed_vars));
};
lp().m_fixed_var_eh = new_fixed;
}
void internalize_is_int(app * n) {
@ -2083,7 +2137,7 @@ public:
}
bool propagate() {
return process_atoms() && propagate_core();
return process_atoms() && propagate_core() && propagate_fixed_vars();
}
bool propagate_core() {