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debug looping behavior

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-12-27 07:50:25 -08:00
parent 58f8181a74
commit 32762b54a7
3 changed files with 34 additions and 13 deletions
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15
src/smt/theory_arith_int.h
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@ -33,11 +33,15 @@ namespace smt {
// Integrality
//
// -----------------------------------
/**
\brief Move non base variables to one of its bounds.
If the variable does not have bounds, it is integer, but it is not assigned to an integer value, then the
variable is set to an integer value.
In mixed integer/real problems moving a real variable to a bound could cause an integer value to
have an infinitesimal. Such an assignment would disable mk_gomory_cut, and Z3 would loop.
*/
template<typename Ext>
void theory_arith<Ext>::move_non_base_vars_to_bounds() {
@ -413,10 +417,10 @@ namespace smt {
for (; it != end; ++it) {
// All non base variables must be at their bounds and assigned to rationals (that is, infinitesimals are not allowed).
if (!it->is_dead() && it->m_var != b && (!at_bound(it->m_var) || !get_value(it->m_var).is_rational())) {
TRACE("gomory_cut", tout << "row is gomory cut target:\n";
TRACE("gomory_cut", tout << "row is not gomory cut target:\n";
display_var(tout, it->m_var);
tout << "at_bound: " << at_bound(it->m_var) << "\n";
tout << "infinitesimal: " << get_value(it->m_var).is_rational() << "\n";);
tout << "infinitesimal: " << !get_value(it->m_var).is_rational() << "\n";);
return false;
}
}
@ -1378,6 +1382,7 @@ namespace smt {
m_branch_cut_counter++;
// TODO: add giveup code
if (m_branch_cut_counter % m_params.m_arith_branch_cut_ratio == 0) {
TRACE("opt", display(tout););
move_non_base_vars_to_bounds();
if (!make_feasible()) {
TRACE("arith_int", tout << "failed to move variables to bounds.\n";);
@ -1389,7 +1394,9 @@ namespace smt {
TRACE("arith_int", tout << "v" << int_var << " does not have an integer assignment: " << get_value(int_var) << "\n";);
SASSERT(is_base(int_var));
row const & r = m_rows[get_var_row(int_var)];
mk_gomory_cut(r);
if (!mk_gomory_cut(r)) {
// silent failure
}
return FC_CONTINUE;
}
}
@ -1399,7 +1406,7 @@ namespace smt {
}
theory_var int_var = find_infeasible_int_base_var();
if (int_var != null_theory_var) {
TRACE("arith_int", tout << "v" << int_var << " does not have and integer assignment: " << get_value(int_var) << "\n";);
TRACE("arith_int", tout << "v" << int_var << " does not have an integer assignment: " << get_value(int_var) << "\n";);
// apply branching
branch_infeasible_int_var(int_var);
return FC_CONTINUE;