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add options to substitute vars in Horner and Grobner

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2020-01-02 15:53:56 -08:00
parent 8596fb2ae6
commit 20af3dd675
7 changed files with 27 additions and 40 deletions
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2
src/math/lp/horner.cpp
View file

@ -78,7 +78,7 @@ bool horner::lemmas_on_row(const T& row) {
SASSERT (row_is_interesting(row));
c().clear_and_resize_active_var_set();
create_sum_from_row(row, cn.get_nex_creator(), m_row_sum, nullptr);
create_sum_from_row(row, cn.get_nex_creator(), m_row_sum);
c().set_active_vars_weights(m_nex_creator); // without this call the comparisons will be incorrect
nex* e = m_nex_creator.simplify(m_row_sum.mk());
TRACE("nla_horner", tout << "e = " << * e << "\n";);

38
src/math/lp/nla_common.cpp
View file

@ -123,17 +123,9 @@ unsigned common::random() {
}
// creates a nex expression for the coeff and var,
nex * common::nexvar(const rational & coeff, lpvar j, nex_creator& cn,
u_dependency*& dep,
u_dependency_manager* dep_manager) {
nex * common::nexvar(const rational & coeff, lpvar j, nex_creator& cn) {
SASSERT(!coeff.is_zero());
unsigned lc, uc;
if (c().var_is_fixed(j)) {
if (dep_manager) {
c().m_lar_solver.get_bound_constraint_witnesses_for_column(j, lc, uc);
dep = dep_manager->mk_join(dep, dep_manager->mk_leaf(lc));
dep = dep_manager->mk_join(dep, dep_manager->mk_leaf(uc));
}
if (c().m_nla_settings.horner_subs_fixed() && c().var_is_fixed(j)) {
return cn.mk_scalar(coeff * c().m_lar_solver.column_lower_bound(j).x);
}
if (!c().is_monic_var(j)) {
@ -144,12 +136,7 @@ nex * common::nexvar(const rational & coeff, lpvar j, nex_creator& cn,
nex_creator::mul_factory mf(cn);
mf *= coeff;
for (lpvar k : m.vars()) {
if (c().var_is_fixed(k)) {
if (dep_manager) {
c().m_lar_solver.get_bound_constraint_witnesses_for_column(k, lc, uc);
dep = dep_manager->mk_join(dep, dep_manager->mk_leaf(lc));
dep = dep_manager->mk_join(dep, dep_manager->mk_leaf(uc));
}
if (c().m_nla_settings.horner_subs_fixed() && c().var_is_fixed(k)) {
mf *= c().m_lar_solver.column_lower_bound(k).x;
} else {
c().insert_to_active_var_set(k);
@ -163,31 +150,20 @@ nex * common::nexvar(const rational & coeff, lpvar j, nex_creator& cn,
}
template <typename T> u_dependency* common::create_sum_from_row(const T& row,
template <typename T> void common::create_sum_from_row(const T& row,
nex_creator& cn,
nex_creator::sum_factory& sum,
u_dependency_manager* dep_manager
nex_creator::sum_factory& sum
) {
TRACE("nla_horner", tout << "row="; m_core->print_row(row, tout) << "\n";);
u_dependency * dep = nullptr;
SASSERT(row.size() > 1);
sum.reset();
for (const auto &p : row) {
nex* e = nexvar(p.coeff(), p.var(), cn, dep, dep_manager);
nex* e = nexvar(p.coeff(), p.var(), cn);
if (!e)
continue;
unsigned lc, uc;
if (dep_manager) {
c().m_lar_solver.get_bound_constraint_witnesses_for_column(p.var(), lc, uc);
if (lc + 1)
dep = dep_manager->mk_join(dep, dep_manager->mk_leaf(lc));
if (uc + 1)
dep = dep_manager->mk_join(dep, dep_manager->mk_leaf(uc));
}
sum += e;
}
return dep;
}
template <typename T>
@ -223,4 +199,4 @@ u_dependency* common::get_fixed_vars_dep_from_row(const T& row, u_dependency_man
}
template u_dependency* nla::common::create_sum_from_row<old_vector<lp::row_cell<rational>, true, unsigned int> >(old_vector<lp::row_cell<rational>, true, unsigned int> const&, nla::nex_creator&, nla::nex_creator::sum_factory&, u_dependency_manager*);
template void nla::common::create_sum_from_row<old_vector<lp::row_cell<rational>, true, unsigned int> >(old_vector<lp::row_cell<rational>, true, unsigned int> const&, nla::nex_creator&, nla::nex_creator::sum_factory&);

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

@ -116,9 +116,9 @@ struct common {
typedef lp::constraint_index value;
};
nex* nexvar(const rational& coeff, lpvar j, nex_creator&, u_dependency*&, u_dependency_manager*);
nex* nexvar(const rational& coeff, lpvar j, nex_creator&);
template <typename T>
u_dependency* create_sum_from_row(const T&, nex_creator&, nex_creator::sum_factory&, u_dependency_manager*);
void create_sum_from_row(const T&, nex_creator&, nex_creator::sum_factory&);
template <typename T>
u_dependency* get_fixed_vars_dep_from_row(const T&, u_dependency_manager& dep_manager);
};

4
src/math/lp/nla_core.cpp
View file

@ -1545,7 +1545,7 @@ const rational& core::val_of_fixed_var_with_deps(lpvar j, u_dependency*& dep) {
}
dd::pdd core::pdd_expr(const rational& c, lpvar j, u_dependency*& dep) {
if (var_is_fixed(j)) {
if (m_nla_settings.grobner_subs_fixed() && var_is_fixed(j)) {
return m_pdd_manager.mk_val(c * val_of_fixed_var_with_deps(j, dep));
}
@ -1556,7 +1556,7 @@ dd::pdd core::pdd_expr(const rational& c, lpvar j, u_dependency*& dep) {
dd::pdd r = m_pdd_manager.mk_val(c);
const monic& m = emons()[j];
for (lpvar k : m.vars()) {
if (var_is_fixed(k)) {
if (m_nla_settings.grobner_subs_fixed() && var_is_fixed(k)) {
r *= m_pdd_manager.mk_val(val_of_fixed_var_with_deps(k, dep));
} else {
r *= m_pdd_manager.mk_var(k);

5
src/math/lp/nla_params.pyg
View file

@ -4,11 +4,12 @@ def_module_params('nla',
('order', BOOL, True, 'run order lemmas'),
('tangents', BOOL, True, 'run tangent lemmas'),
('horner', BOOL, True, 'run horner\'s heuristic'),
('horner_subs_fixed', BOOL, True, 'substitute fixed variables by constants'),
('horner_frequency', UINT, 4, 'horner\'s call frequency'),
('horner_row_length_limit', UINT, 10, 'row is disregarded by the heuristic if its length is longer than the value'),
('grobner', BOOL, True, 'run grobner\'s basis heuristic'),
('grobner_frequency', UINT, 5, 'grobner\'s call frequency'),
('grobner_eqs_threshold', UINT, 512, 'grobner\'s maximum number of equalities')
('grobner_eqs_threshold', UINT, 512, 'grobner\'s maximum number of equalities'),
('grobner_subs_fixed', BOOL, False, 'substitute fixed variables by constants')
))

11
src/math/lp/nla_settings.h
View file

@ -27,18 +27,21 @@ class nla_settings {
// how often to call the horner heuristic
unsigned m_horner_frequency;
unsigned m_horner_row_length_limit;
bool m_horner_subs_fixed;
// grobner fields
bool m_run_grobner;
unsigned m_grobner_row_length_limit;
bool m_grobner_subs_fixed;
public:
nla_settings() : m_run_order(true),
m_run_tangents(true),
m_run_horner(true),
m_horner_frequency(4),
m_horner_row_length_limit(10),
m_horner_subs_fixed(true),
m_run_grobner(true),
m_grobner_row_length_limit(50)
m_grobner_row_length_limit(50),
m_grobner_subs_fixed(false)
{}
bool run_order() const { return m_run_order; }
@ -54,11 +57,15 @@ public:
unsigned& horner_frequency() { return m_horner_frequency; }
unsigned horner_row_length_limit() const { return m_horner_row_length_limit; }
unsigned& horner_row_length_limit() { return m_horner_row_length_limit; }
bool horner_subs_fixed() const { return m_horner_subs_fixed; }
bool& horner_subs_fixed() { return m_horner_subs_fixed; }
bool run_grobner() const { return m_run_grobner; }
bool& run_grobner() { return m_run_grobner; }
unsigned grobner_row_length_limit() const { return m_grobner_row_length_limit; }
unsigned& grobner_row_length_limit() { return m_grobner_row_length_limit; }
bool grobner_subs_fixed() const { return m_grobner_subs_fixed; }
bool& grobner_subs_fixed() { return m_grobner_subs_fixed; }
};
}

3
src/smt/theory_lra.cpp
View file

@ -450,9 +450,12 @@ class theory_lra::imp {
m_nla->get_core()->m_nla_settings.run_order() = nla.order();
m_nla->get_core()->m_nla_settings.run_tangents() = nla.tangents();
m_nla->get_core()->m_nla_settings.run_horner() = nla.horner();
m_nla->get_core()->m_nla_settings.horner_subs_fixed() = nla.horner_subs_fixed();
m_nla->get_core()->m_nla_settings.horner_frequency() = nla.horner_frequency();
m_nla->get_core()->m_nla_settings.horner_row_length_limit() = nla.horner_row_length_limit();
m_nla->get_core()->m_nla_settings.run_grobner() = nla.grobner();
m_nla->get_core()->m_nla_settings.grobner_subs_fixed() = nla.grobner_subs_fixed();
}
}