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toward order lemma

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Signed-off-by: Lev <levnach@hotmail.com>
This commit is contained in:
Lev 2018-11-30 16:46:03 -08:00 committed by Lev Nachmanson
parent 82589ad325
commit a5c146a740
2 changed files with 122 additions and 39 deletions
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2
src/util/lp/factorization.h
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@ -26,7 +26,7 @@ namespace nla {
struct factorization_factory;
typedef unsigned lpvar;
enum class factor_type { VAR, RM}; // RM stands for rooted monomial
enum class factor_type { VAR, RM }; // RM stands for rooted monomial
class factor {
unsigned m_index;

159
src/util/lp/nla_solver.cpp
View file

@ -26,15 +26,92 @@
namespace nla {
// returns true if a factor of b
template <typename T>
bool is_factor(const T & a, const T & b) {
SASSERT(lp::is_non_decreasing(a) && lp::is_non_decreasing(b));
auto i = a.begin();
auto j = b.begin();
while (true) {
if (i == a.end()) {
return true;
}
if (j == b.end()) {
return false;
}
if (*i == *j) {
i++;j++;
continue;
}
i++;
}
}
// b / a, where a is a factor of b and both vectors are sorted
template <typename T>
svector<unsigned> vector_div(const T & b, const T & a) {
SASSERT(lp::is_non_decreasing(a));
SASSERT(lp::is_non_decreasing(b));
SASSERT(is_factor(a, b));
svector<unsigned> r;
auto i = a.begin();
auto j = b.begin();
while (true) {
if (j == b.end()) {
break;
}
if (i == a.end()) {
r.push_back(*j);
j++;
continue;
}
if (*i == *j) {
i++;j++;
continue;
}
r.push_back(*j);
j++;
}
return r;
}
// bool is_factor(const T a, const T b ) {
// SASSERT(is_sorted(a) && is_sorted(b));
// if (b.size() <= a.size())
// return false;
// while (!b.empty() && !a.empty() ) {
// if (b.back() < a.back())
// return false;
// if (b.back() == a.back()) {
// a.pop_back(); b.pop_back();
// } else { // b.back() > a.back()
// b.pop_back();
// }
// }
// return a.empty();
// }
struct solver::imp {
struct rooted_mon {
svector<lpvar> m_vars;
index_with_sign m_orig;
rooted_mon(const svector<lpvar>& vars, unsigned i, const rational& sign): m_vars(vars), m_orig(i, sign) {}
rooted_mon(const svector<lpvar>& vars, unsigned i, const rational& sign): m_vars(vars), m_orig(i, sign) {
SASSERT(lp::is_non_decreasing(vars));
}
lpvar operator[](unsigned k) const { return m_vars[k];}
unsigned size() const { return m_vars.size(); }
unsigned orig_index() const { return m_orig.m_i; }
const rational& orig_sign() const { return m_orig.m_sign; }
const svector<lpvar> & vars() const {return m_vars;}
};
@ -96,6 +173,14 @@ struct solver::imp {
return f.is_var()?
f.index() : orig_mon_var(m_vector_of_rooted_monomials[f.index()]);
}
svector<lpvar> sorted_vars(const factor& f) const {
if (f.is_var()) {
svector<lpvar> r; r.push_back(f.index());
return r;
}
return m_vector_of_rooted_monomials[f.index()].vars();
}
rational flip_sign(const factor& f) const {
return f.is_var()?
@ -199,16 +284,26 @@ struct solver::imp {
print_product(m, out);
out << '\n';
for (unsigned k = 0; k < m.size(); k++) {
print_var(m.vars()[k], out);
print_var(m[k], out);
}
return out;
}
std::ostream& print_monomial_with_vars(const monomial& m, std::ostream& out) const {
out << m_lar_solver.get_variable_name(m.var()) << " = ";
return print_product_with_vars(m, out);
}
std::ostream& print_rooted_monomial(const rooted_mon& rm, std::ostream& out) const {
out << "vars = ";
print_product_with_vars(rm.vars(), out);
out << "\n orig = "; print_monomial_with_vars(m_monomials[rm.orig_index()], out);
out << ", orig sign = " << rm.orig_sign() << "\n";
return out;
}
std::ostream& print_explanation(std::ostream& out) const {
for (auto &p : *m_expl) {
@ -865,29 +960,6 @@ struct solver::imp {
}
// returns true if a is a factar of b
bool is_factor(const svector<lpvar> & a, const svector<lpvar> & b) {
SASSERT(lp::is_non_decreasing(a) && lp::is_non_decreasing(b));
auto i = a.begin();
auto j = b.begin();
while (true) {
if (i == a.end()) {
return true;
}
if (j == b.end()) {
return false;
}
j = std::lower_bound(j, b.end(), *i);
if (j == b.end() || *i != *j) {
return false;
}
i++; j++;
}
}
void reduce_set_by_checking_actual_containment(std::unordered_set<unsigned>& p,
const rooted_mon & rm ) {
@ -957,18 +1029,32 @@ struct solver::imp {
m_lemma->clear();
}
static svector<lpvar> extract_all_but(const svector<lpvar> & vars, unsigned k) {
static svector<lpvar> ret;
for (unsigned j = 0; j < vars.size(); j++) {
if (j == k)
continue;
ret.push_back(vars[j]);
}
return ret;
bool divide(const rooted_mon& bc, const factor& c, factor & b) const {
svector<lpvar> c_vars = sorted_vars(c);
TRACE("nla_solver",
tout << "c_vars = ";
print_product(c_vars, tout);
tout << "\nbc_vars = ";
print_product(bc.vars(), tout););
auto b_vars = vector_div(bc.vars(), sorted_vars(c));
TRACE("nla_solver", tout << "b_vars = "; print_product(b_vars, tout););
return false;
}
bool order_lemma_on_ac_and_bc(const rooted_mon& rm, const factorization& ac, unsigned k, const rooted_mon& rm_bc) {
NOT_IMPLEMENTED_YET();
// a > b && c > 0 => ac > bc
// ac is a factorization of m_monomials[i_mon]
// ac[k] plays the role of c
bool order_lemma_on_ac_and_bc(const rooted_mon& rm, const factorization& acf, unsigned k, const rooted_mon& rm_bc) {
TRACE("nla_solver",
tout << "rm = ";
print_rooted_monomial(rm, tout);
tout << "factor, c = "; print_factor(acf[k], tout);
tout << "\nrm_bc = ";
print_rooted_monomial(rm_bc, tout););
factor b;
if (!divide(rm, acf[k], b))
return false;
return false;
}
@ -980,8 +1066,6 @@ struct solver::imp {
TRACE("nla_solver", tout << "k = " << k << ", c = "; print_factor(c, tout); );
if (c.is_var()) {
TRACE("nla_solver", );
for (unsigned rm_bc : m_rooted_monomials_containing_var[var(c)]) {
TRACE("nla_solver", );
if (order_lemma_on_ac_and_bc(rm , ac, k, m_vector_of_rooted_monomials[rm_bc])) {
@ -989,7 +1073,6 @@ struct solver::imp {
}
}
} else {
TRACE("nla_solver", );
for (unsigned rm_bc : m_rooted_factor_to_product[var(c)]) {
TRACE("nla_solver", );
if (order_lemma_on_ac_and_bc(rm , ac, k, m_vector_of_rooted_monomials[rm_bc])) {