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add conflict detection for a list of monomials having the same rooted monomial

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Signed-off-by: Lev <levnach@hotmail.com>
This commit is contained in:
Lev 2018-10-01 11:52:17 -07:00 committed by Lev Nachmanson
parent ee2aed38e8
commit e7441cf01e
1 changed files with 20 additions and 61 deletions
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81
src/util/lp/nla_solver.cpp
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@ -222,30 +222,6 @@ struct solver::imp {
/**
* \brief <here we have two monomials, i_mon and other_m, examined for "sign" equivalence>
*/
// If we see that monomials are the same up to the sign,
// but the values are not equal up to the sign, we generate a lemman and a conflict explanation
bool generate_basic_lemma_for_mon_sign_var_other_mon(
unsigned i_mon,
unsigned j_var,
const unsigned_vector & mon_vars,
const mon_eq& other_m, int sign) {
if (mon_vars.size() != other_m.size())
return false;
auto other_vars_copy = other_m.vars();
int other_sign = 1;
reduce_monomial_to_canonical(other_vars_copy, other_sign);
if (mon_vars == other_vars_copy &&
values_are_different(m_monomials[i_mon].var(), sign * other_sign, other_m.var())) {
fill_explanation_and_lemma_sign(m_monomials[i_mon],
other_m,
sign * other_sign);
TRACE("nla_solver", tout << "lemma generated\n";);
return true;
}
return false;
}
bool values_are_different(lpvar j, int sign, lpvar k) const {
SASSERT(sign == 1 || sign == -1);
@ -302,25 +278,6 @@ struct solver::imp {
ineq in(lp::lconstraint_kind::NE, t, rational::zero());
m_lemma->push_back(in);
}
/**
* \brief <go over monomials containing j_var and generate the sign lemma
*/
bool generate_basic_lemma_for_mon_sign_var(unsigned i_mon,
unsigned j_var, const svector<lpvar>& mon_vars, int sign) {
auto it = m_var_lists.find(j_var);
for (auto other_i_mon : it->second) {
if (other_i_mon == i_mon) continue;
if (generate_basic_lemma_for_mon_sign_var_other_mon(
i_mon,
j_var,
mon_vars,
m_monomials[other_i_mon],
sign))
return true;
}
return false;
}
// Replaces each variable index by the root in the tree and flips the sign if the var comes with a minus.
//
@ -344,14 +301,24 @@ struct solver::imp {
if (m_vars_equivalence.empty()) {
return false;
}
const mon_eq& m_of_i = m_monomials[i_mon];
int sign = 1;
for (auto it : m_rooted_monomials) {
const auto & list = it.second;
const auto & m0 = list[0];
rational val = vvr(m_monomials[m0.m_i].var()) * m0.m_sign;
// every other monomial in the list has to have the same value up to the sign
for (unsigned i = 1; i < list.size(); i++) {
const auto & mi = list[i];
rational other_val = vvr(m_monomials[mi.m_i].var()) * mi.m_sign;
if (val != other_val) {
fill_explanation_and_lemma_sign(m_monomials[m0.m_i],
m_monomials[mi.m_i],
m0.m_sign * mi.m_sign);
return true;
}
}
}
auto mon_vars = m_of_i.vars();
reduce_monomial_to_canonical(mon_vars, sign);
for (unsigned j_var : mon_vars)
if (generate_basic_lemma_for_mon_sign_var(i_mon, j_var, mon_vars, sign))
return true;
return false;
}
@ -652,8 +619,6 @@ struct solver::imp {
if (ones_of_mon.empty()) {
return false;
}
if (m_rooted_monomials.empty() && m.size() > 2)
create_min_mon_map();
return process_ones_of_mon(m, ones_of_mon, vars, v);
}
@ -961,9 +926,6 @@ struct solver::imp {
if (large.empty() && _small.empty())
return false;
if (m_rooted_monomials.empty())
create_min_mon_map();
if (!large.empty() && large_basic_lemma_for_mon_proportionality(i_mon, large))
return true;
@ -1263,8 +1225,6 @@ struct solver::imp {
return true;
}
}
// return true;
SASSERT(false);
return false;
}
@ -1380,8 +1340,8 @@ struct solver::imp {
svector<lpvar> key = reduce_monomial_to_canonical(m.vars(), sign);
register_key_mono_in_min_monomials(key, i, sign);
}
void create_min_mon_map() {
void create_rooted_monomials_map() {
for (unsigned i = 0; i < m_monomials.size(); i++)
register_monomial_in_min_map(i);
}
@ -1389,6 +1349,7 @@ struct solver::imp {
void init_search() {
map_vars_to_monomials_and_constraints();
init_vars_equivalence();
create_rooted_monomials_map();
m_expl->clear();
m_lemma->clear();
}
@ -1422,8 +1383,6 @@ struct solver::imp {
lp::explanation exp;
m_expl = & exp;
init_search();
if (m_rooted_monomials.empty())
create_min_mon_map();
binary_factorizations_of_monomial fc(0, // 0 is the index of "abcde"
*this);