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fix the infeasibility bug

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2025-03-07 12:55:09 -10:00
parent 50fd572e66
commit 4068720d06
1 changed files with 9 additions and 5 deletions
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14
src/math/lp/dioph_eq.cpp
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@ -1821,7 +1821,7 @@ namespace lp {
rs = (rs - m_c) / g;
TRACE("dio", tout << "((rs - m_c) / g):" << rs << std::endl;);
if (!rs.is_int()) {
if (tighten_bound_kind(g, j, rs, is_upper, b_dep))
if (tighten_bound_kind(g, j, rs, is_upper))
return lia_move::conflict;
} else {
TRACE("dio", tout << "no improvement in the bound\n";);
@ -1832,8 +1832,7 @@ namespace lp {
}
// returns true only on a conflict
bool tighten_bound_kind(const mpq& g, unsigned j, const mpq& ub, bool upper,
u_dependency* prev_dep) {
bool tighten_bound_kind(const mpq& g, unsigned j, const mpq& ub, bool upper) {
// ub = (upper_bound(j) - m_c)/g.
// we have xj = t = g*t_+ m_c <= upper_bound(j), then
// t_ <= floor((upper_bound(j) - m_c)/g) = floor(ub)
@ -1849,7 +1848,7 @@ namespace lp {
SASSERT((upper && bound < lra.get_upper_bound(j).x) ||
(!upper && bound > lra.get_lower_bound(j).x));
lconstraint_kind kind = upper ? lconstraint_kind::LE : lconstraint_kind::GE;
u_dependency* dep = prev_dep;
u_dependency* dep = lra.get_bound_constraint_witnesses_for_column(j);
dep = lra.join_deps(dep, explain_fixed_in_meta_term(m_lspace.m_data));
u_dependency* j_bound_dep = upper ? lra.get_column_upper_bound_witness(j) : lra.get_column_lower_bound_witness(j);
dep = lra.join_deps(dep, j_bound_dep);
@ -1858,6 +1857,11 @@ namespace lp {
print_lar_term_L(lra.get_term(j), tout) << "\ndep:";
print_deps(tout, dep) << std::endl;);
lra.update_column_type_and_bound(j, kind, bound, dep);
if (lra.settings().dump_bound_lemmas()) {
std::string lemma_name = "lemma" + std::to_string(m_n_of_lemmas++);
lra.write_bound_lemma_to_file(j, !upper, lemma_name, std::string( __FILE__)+ ","+ std::to_string(__LINE__));
}
lp_status st = lra.find_feasible_solution();
if ((int)st >= (int)lp::lp_status::FEASIBLE) {
m_tightened_columns.insert(j);
@ -2554,7 +2558,7 @@ namespace lp {
for (const auto& v : ml) {
for (const auto & p : lra.get_term(v.var()).ext_coeffs()) {
if (lra.column_is_fixed(p.var()))
r.add(p.coeff(), p.var());
r.add(v.coeff()*p.coeff(), p.var());
}
}
return r;