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simplifying Grobner's schema

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2019-12-05 18:33:35 -10:00
parent e62913999e
commit a7aa099101
2 changed files with 17 additions and 44 deletions
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57
src/math/lp/nla_grobner.cpp
View file

@ -219,11 +219,9 @@ nla_grobner::equation* nla_grobner::simplify_using_processed(equation* eq) {
do { do {
simplified = false; simplified = false;
for (equation * p : m_to_superpose) { for (equation * p : m_to_superpose) {
equation * new_eq = simplify_source_target(p, eq); if (simplify_source_target(p, eq)) {
if (new_eq) {
result = true; result = true;
simplified = true; simplified = true;
eq = new_eq;
} }
if (canceled()) { if (canceled()) {
return nullptr; return nullptr;
@ -422,19 +420,19 @@ void nla_grobner::simplify_target_monomials_sum_j(equation * source, equation *t
TRACE("grobner_d", tout << "targ_sum = " << *targ_sum << "\n";); TRACE("grobner_d", tout << "targ_sum = " << *targ_sum << "\n";);
} }
// return true iff simplified
nla_grobner::equation * nla_grobner::simplify_source_target(equation * source, equation * target) { bool nla_grobner::simplify_source_target(equation * source, equation * target) {
TRACE("grobner", tout << "simplifying: "; display_equation(tout, *target); tout << "using: "; display_equation(tout, *source);); TRACE("grobner", tout << "simplifying: "; display_equation(tout, *target); tout << "using: "; display_equation(tout, *source););
TRACE("grobner_d", tout << "simplifying: " << *(target->exp()) << " using " << *(source->exp()) << "\n";); TRACE("grobner_d", tout << "simplifying: " << *(target->exp()) << " using " << *(source->exp()) << "\n";);
SASSERT(m_nex_creator.is_simplified(source->exp())); SASSERT(m_nex_creator.is_simplified(source->exp()));
SASSERT(m_nex_creator.is_simplified(target->exp())); SASSERT(m_nex_creator.is_simplified(target->exp()));
if (target->exp()->is_scalar()) { if (target->exp()->is_scalar()) {
TRACE("grobner_d", tout << "no simplification\n";); TRACE("grobner_d", tout << "no simplification\n";);
return nullptr; return false;
} }
if (source->get_num_monomials() == 0) { if (source->get_num_monomials() == 0) {
TRACE("grobner_d", tout << "no simplification\n";); TRACE("grobner_d", tout << "no simplification\n";);
return nullptr; return false;
} }
m_stats.m_simplify++; m_stats.m_simplify++;
bool result = false; bool result = false;
@ -450,29 +448,18 @@ nla_grobner::equation * nla_grobner::simplify_source_target(equation * source, e
if (result) { if (result) {
target->dep() = m_dep_manager.mk_join(target->dep(), source->dep()); target->dep() = m_dep_manager.mk_join(target->dep(), source->dep());
TRACE("grobner_d", tout << "simplied to " << *(target->exp()) << "\n";); TRACE("grobner_d", tout << "simplied to " << *(target->exp()) << "\n";);
return target; return true;
} }
TRACE("grobner_d", tout << "no simplification\n";); TRACE("grobner_d", tout << "no simplification\n";);
return nullptr; return false;
} }
void nla_grobner::process_simplified_target(ptr_buffer<equation>& to_insert, equation* new_target, equation*& target, ptr_buffer<equation>& to_remove) { void nla_grobner::process_simplified_target(equation* target, ptr_buffer<equation>& to_remove) {
if (new_target != target) { if (is_trivial(target)) {
to_remove.push_back(target);
} else if (m_changed_leading_term) {
insert_to_simplify(target);
to_remove.push_back(target); to_remove.push_back(target);
if (m_changed_leading_term) {
insert_to_simplify(new_target);
to_remove.push_back(target);
}
else {
to_insert.push_back(new_target);
}
target = new_target;
}
else {
if (m_changed_leading_term) {
insert_to_simplify(target);
to_remove.push_back(target);
}
} }
} }
@ -500,9 +487,8 @@ bool nla_grobner::simplify_to_superpose_with_eq(equation* eq) {
equation * target = *it; equation * target = *it;
m_changed_leading_term = false; m_changed_leading_term = false;
// if the leading term is simplified, then the equation has to be moved to m_to_simplify // if the leading term is simplified, then the equation has to be moved to m_to_simplify
equation * new_target = simplify_source_target(eq, target); if (simplify_source_target(eq, target)) {
if (new_target != nullptr) { process_simplified_target(target, to_remove);
process_simplified_target(to_insert, new_target, target, to_remove);
} }
if (is_trivial(target)) if (is_trivial(target))
to_delete.push_back(target); to_delete.push_back(target);
@ -520,26 +506,13 @@ bool nla_grobner::simplify_to_superpose_with_eq(equation* eq) {
void nla_grobner::simplify_to_superpose(equation* eq) { void nla_grobner::simplify_to_superpose(equation* eq) {
TRACE("grobner_d", tout << "eq->exp " << *(eq->exp()) << "\n";); TRACE("grobner_d", tout << "eq->exp " << *(eq->exp()) << "\n";);
ptr_buffer<equation> to_insert;
ptr_buffer<equation> to_remove;
ptr_buffer<equation> to_delete; ptr_buffer<equation> to_delete;
for (equation* target : m_to_simplify) { for (equation* target : m_to_simplify) {
equation * new_target = simplify_source_target(eq, target); if (simplify_source_target(eq, target) && is_trivial(target))
if (new_target != nullptr && new_target != target) {
to_insert.push_back(new_target);
to_remove.push_back(target);
target = new_target;
}
if (is_trivial(target))
to_delete.push_back(target); to_delete.push_back(target);
} }
for (equation* eq : to_insert)
insert_to_simplify(eq);
for (equation* eq : to_remove)
m_to_simplify.erase(eq);
for (equation* eq : to_delete) for (equation* eq : to_delete)
del_equation(eq); del_equation(eq);
} }
// if e is the sum then add to r all children of e multiplied by beta, except the first one // if e is the sum then add to r all children of e multiplied by beta, except the first one

4
src/math/lp/nla_grobner.h
View file

@ -112,10 +112,10 @@ private:
void compute_basis_init(); void compute_basis_init();
bool compute_basis_loop(); bool compute_basis_loop();
bool compute_basis_step(); bool compute_basis_step();
equation * simplify_source_target(equation * source, equation * target); bool simplify_source_target(equation * source, equation * target);
equation* simplify_using_processed(equation*); equation* simplify_using_processed(equation*);
bool simplify_target_monomials(equation * source, equation * target); bool simplify_target_monomials(equation * source, equation * target);
void process_simplified_target(ptr_buffer<equation>& to_insert, equation* new_target, equation*& target, ptr_buffer<equation>& to_remove); void process_simplified_target(equation* target, ptr_buffer<equation>& to_remove);
bool simplify_to_superpose_with_eq(equation*); bool simplify_to_superpose_with_eq(equation*);
void simplify_to_superpose(equation*); void simplify_to_superpose(equation*);
equation* pick_next(); equation* pick_next();