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fixes in dio branching

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2024-11-19 11:49:14 -08:00 • committed by Lev Nachmanson
parent 6bc7662580
commit 63980f3bfd
1 changed files with 24 additions and 17 deletions
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41
src/math/lp/dioph_eq.cpp
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@ -892,7 +892,10 @@ namespace lp {
TRACE("dio_br",
tout << "fixed j:" << j <<", was substited by "; print_entry(m_k2s[j], tout););
if (check_fixing(j) == lia_move::conflict) {
m_conflict_index = m_k2s[j];
auto& ep = m_entries[m_k2s[j]];
for (auto ci : lra.flatten(explain_fixed_in_meta_term(ep.m_l))) {
m_explanation_of_branches.push_back(ci);
}
return lia_move::conflict;
}
}
@ -917,15 +920,18 @@ namespace lp {
return true;
}
lia_move add_var_bound_for_branch(const branch* b) {
if (b->m_left) {
lra.add_var_bound(b->m_j, lconstraint_kind::LE, b->m_rs);
} else {
lra.add_var_bound(b->m_j, lconstraint_kind::GE, b->m_rs + mpq(1));
lia_move add_var_bound_for_branch(const branch& b) {
if (b.m_left) {
lra.add_var_bound(b.m_j, lconstraint_kind::LE, b.m_rs);
} else {
lra.add_var_bound(b.m_j, lconstraint_kind::GE, b.m_rs + mpq(1));
}
if (lra.column_is_fixed(b->m_j)) {
if (fix_var(lar_solver_to_local(b->m_j)) == lia_move::conflict)
TRACE("dio_br", lra.print_column_info(b.m_j, tout) <<"add bound" << std::endl;);
if (lra.column_is_fixed(b.m_j)) {
if (fix_var(lar_solver_to_local(b.m_j)) == lia_move::conflict) {
TRACE("dio_br", tout << "conflict in fix_var" << std::endl;) ;
return lia_move::conflict;
}
}
return lia_move::undef;
}
@ -955,7 +961,6 @@ namespace lp {
lia_move branching_on_undef() {
m_explanation_of_branches.clear();
branch* b;
bool need_create_branch = true;
m_number_of_iterations = 0;
while (++m_number_of_iterations < m_max_number_of_iterations) {
@ -967,25 +972,23 @@ namespace lp {
return lia_move::sat;
}
need_create_branch = false;
b = &m_branch_stack.back();
}
lra_push(); // exploring a new branch
if (add_var_bound_for_branch(b) == lia_move::conflict) {
collect_evidence();
if (add_var_bound_for_branch(m_branch_stack.back()) == lia_move::conflict) {
undo_explored_branches();
if (m_branch_stack.size() == 0) {
lra.stats().m_dio_branching_infeasibles++;
transfer_explanations_from_closed_branches();
return lia_move::conflict;
}
TRACE("dio_br", tout << lp_status_to_string(lra.get_status()) << std::endl;
tout << "explanation:\n"; lra.print_expl(tout, m_infeas_explanation););
need_create_branch = false;
m_branch_stack.back().flip();
lra_pop();
continue;
}
auto st = lra.find_feasible_solution();
TRACE("dio_br", tout << "st:" << lp_status_to_string(st) << std::endl;);
if ((int)st >= (int)(lp_status::FEASIBLE)) {
// have a feasible solution
unsigned n_of_ii = get_number_of_int_inf();
@ -996,7 +999,7 @@ namespace lp {
return lia_move::sat;
}
// got to create a new branch
update_branch_stats(*b, n_of_ii);
update_branch_stats(m_branch_stack.back(), n_of_ii);
need_create_branch = true;
} else {
if (st == lp_status::CANCELLED) return lia_move::undef;
@ -1089,6 +1092,8 @@ namespace lp {
public:
lia_move check() {
++glb;
TRACE("dioph_eq", tout << "glb:" << glb << std::endl; );
lra.stats().m_dio_calls++;
init();
lia_move ret = process_f_and_tighten_terms();
@ -1096,8 +1101,10 @@ namespace lp {
return ret;
SASSERT(ret == lia_move::undef);
ret = branching_on_undef();
if (ret == lia_move::sat || ret == lia_move::conflict)
return ret;
if (ret == lia_move::sat || ret == lia_move::conflict) {
SASSERT(lra.settings().get_cancel_flag() == false);
return ret;
}
SASSERT(ret == lia_move::undef);
return lia_move::undef;
}