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fix bug in bound simplification in Gomory for mixed integer linear cuts, enable fixed variable redution after bugfix, add notes that rewriting bounds does not work

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2023-11-10 16:38:55 +01:00
parent aa9c7912dc
commit 3de5af3cb0
5 changed files with 121 additions and 261 deletions
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40
src/math/lp/hnf_cutter.cpp
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@ -83,14 +83,13 @@ namespace lp {
// consider return from here if b[i] is not an integer and return i
}
}
vector<mpq> hnf_cutter::create_b(const svector<unsigned> & basis_rows) {
if (basis_rows.size() == m_right_sides.size())
return m_right_sides;
vector<mpq> b;
for (unsigned i : basis_rows) {
b.push_back(m_right_sides[i]);
}
for (unsigned i : basis_rows)
b.push_back(m_right_sides[i]);
return b;
}
@ -98,16 +97,15 @@ namespace lp {
int ret = -1;
int n = 0;
for (int i = 0; i < static_cast<int>(b.size()); i++) {
if (is_integer(b[i])) continue;
if (n == 0 ) {
if (is_integer(b[i]))
continue;
if (n == 0) {
lp_assert(ret == -1);
n = 1;
ret = i;
} else {
if (m_settings.random_next() % (++n) == 0) {
ret = i;
}
}
else if (m_settings.random_next() % (++n) == 0)
ret = i;
}
return ret;
}
@ -240,10 +238,7 @@ branch y_i >= ceil(y0_i) is impossible.
}
bool hnf_cutter::hnf_has_var_with_non_integral_value() const {
for (unsigned j : vars())
if (!lia.get_value(j).is_int())
return true;
return false;
return any_of(vars(), [&](unsigned j) { return !lia.get_value(j).is_int(); });
}
bool hnf_cutter::init_terms_for_hnf_cut() {
@ -252,17 +247,15 @@ branch y_i >= ceil(y0_i) is impossible.
try_add_term_to_A_for_hnf(tv::term(i));
return hnf_has_var_with_non_integral_value();
}
lia_move hnf_cutter::make_hnf_cut() {
if (!init_terms_for_hnf_cut()) {
if (!init_terms_for_hnf_cut())
return lia_move::undef;
}
lia.settings().stats().m_hnf_cutter_calls++;
TRACE("hnf_cut", tout << "settings().stats().m_hnf_cutter_calls = " << lia.settings().stats().m_hnf_cutter_calls << "\n";
for (u_dependency* d : constraints_for_explanation()) {
for (auto ci : lra.flatten(d))
lra.constraints().display(tout, ci);
}
for (u_dependency* d : constraints_for_explanation())
for (auto ci : lra.flatten(d))
lra.constraints().display(tout, ci);
tout << lra.constraints();
);
#ifdef Z3DEBUG
@ -273,14 +266,14 @@ branch y_i >= ceil(y0_i) is impossible.
, x0
#endif
);
if (r == lia_move::cut) {
TRACE("hnf_cut",
lra.print_term(lia.m_t, tout << "cut:");
tout << " <= " << lia.m_k << std::endl;
for (auto* dep : constraints_for_explanation())
for (auto ci : lra.flatten(dep))
lra.constraints().display(tout, ci);
lra.constraints().display(tout, ci);
);
lp_assert(lia.current_solution_is_inf_on_cut());
lia.settings().stats().m_hnf_cuts++;
@ -291,5 +284,4 @@ branch y_i >= ceil(y0_i) is impossible.
}
return r;
}
}