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adding pdd-grobner

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-12-18 12:03:13 -08:00
parent ca0a52c930
commit 5e0799225d
6 changed files with 441 additions and 2 deletions
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50
src/math/dd/dd_pdd.cpp
View file

@ -338,6 +338,56 @@ namespace dd {
}
}
/*
* Compare leading monomials.
* The pdd format makes lexicographic comparison easy: compare based on
* the top variable and descend depending on whether hi(x) == hi(y)
*/
bool pdd_manager::lt(pdd const& a, pdd const& b) {
PDD x = a.root;
PDD y = b.root;
if (x == y) return false;
while (true) {
SASSERT(x != y);
if (is_val(x))
return !is_val(y) || val(x) < val(y);
if (is_val(y))
return false;
if (level(x) == level(y)) {
if (hi(x) == hi(y)) {
x = lo(x);
y = lo(y);
}
else {
x = hi(x);
y = hi(y);
}
}
else {
return level(x) > level(y);
}
}
}
/**
Compare leading terms of pdds
*/
bool pdd_manager::different_leading_term(pdd const& a, pdd const& b) {
PDD x = a.root;
PDD y = b.root;
while (true) {
if (x == y) return false;
if (is_val(x) || is_val(y)) return true;
if (level(x) == level(y)) {
x = hi(x);
y = hi(y);
}
else {
return false;
}
}
}
void pdd_manager::push(PDD b) {
m_pdd_stack.push_back(b);
}

11
src/math/dd/dd_pdd.h
View file

@ -141,7 +141,6 @@ namespace dd {
small_object_allocator m_alloc;
mutable svector<unsigned> m_mark;
mutable unsigned m_mark_level;
mutable svector<double> m_count;
mutable svector<PDD> m_todo;
bool m_disable_gc;
bool m_is_new_node;
@ -230,6 +229,8 @@ namespace dd {
pdd mul(rational const& c, pdd const& b);
pdd reduce(pdd const& a, pdd const& b);
bool try_spoly(pdd const& a, pdd const& b, pdd& r);
bool lt(pdd const& a, pdd const& b);
bool different_leading_term(pdd const& a, pdd const& b);
std::ostream& display(std::ostream& out);
std::ostream& display(std::ostream& out, pdd const& b);
@ -243,7 +244,8 @@ namespace dd {
pdd_manager* m;
pdd(unsigned root, pdd_manager* m): root(root), m(m) { m->inc_ref(root); }
public:
pdd(pdd & other): root(other.root), m(other.m) { m->inc_ref(root); }
pdd(pdd_manager& pm): root(0), m(&pm) { SASSERT(is_zero()); }
pdd(pdd const& other): root(other.root), m(other.m) { m->inc_ref(root); }
pdd(pdd && other): root(0), m(other.m) { std::swap(root, other.root); }
pdd& operator=(pdd const& other);
~pdd() { m->dec_ref(root); }
@ -252,6 +254,7 @@ namespace dd {
unsigned var() const { return m->var(root); }
rational const& val() const { SASSERT(is_val()); return m->val(root); }
bool is_val() const { return m->is_val(root); }
bool is_zero() const { return m->is_zero(root); }
pdd operator+(pdd const& other) const { return m->add(*this, other); }
pdd operator-(pdd const& other) const { return m->sub(*this, other); }
@ -259,10 +262,13 @@ namespace dd {
pdd operator*(rational const& other) const { return m->mul(other, *this); }
pdd operator+(rational const& other) const { return m->add(other, *this); }
pdd reduce(pdd const& other) const { return m->reduce(*this, other); }
bool different_leading_term(pdd const& other) const { return m->different_leading_term(*this, other); }
std::ostream& display(std::ostream& out) const { return m->display(out, *this); }
bool operator==(pdd const& other) const { return root == other.root; }
bool operator!=(pdd const& other) const { return root != other.root; }
bool operator<(pdd const& b) const { return m->lt(*this, b); }
unsigned size() const { return m->pdd_size(*this); }
};
@ -276,6 +282,7 @@ namespace dd {
inline pdd operator-(pdd const& b, int x) { return b + (-rational(x)); }
std::ostream& operator<<(std::ostream& out, pdd const& b);
}