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process with nex simplifications

Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2019-09-26 17:18:45 -07:00
parent c076c17df9
commit 8cd9989dcf
5 changed files with 122 additions and 78 deletions

View file

@ -36,12 +36,12 @@ class cross_nested {
bool m_random_bit;
nex_creator m_nex_creator;
nex_lt m_lt;
std::function<nex_scalar*()> m_mk_scalar;
#ifdef Z3DEBUG
nex* m_e_clone;
#endif
public:
nex_creator& get_nex_creator() { return m_nex_creator; }
cross_nested(std::function<bool (const nex*)> call_on_result,
@ -54,7 +54,9 @@ public:
m_done(false),
m_reported(0),
m_nex_creator(lt),
m_lt(lt) {}
m_lt(lt),
m_mk_scalar([this]{return m_nex_creator.mk_scalar(rational(1));})
{}
void run(nex *e) {
@ -128,7 +130,7 @@ public:
}
nex* c_over_f = m_nex_creator.mk_div(*c, f);
to_sum(c_over_f)->simplify(&c_over_f, m_lt);
to_sum(c_over_f)->simplify(&c_over_f, m_lt, m_mk_scalar);
nex_mul* cm;
*c = cm = m_nex_creator.mk_mul(f, c_over_f);
TRACE("nla_cn", tout << "common factor=" << *f << ", c=" << **c << "\ne = " << *m_e << "\n";);
@ -393,7 +395,7 @@ public:
TRACE("nla_cn_details", tout << "a = " << *a << "\n";);
SASSERT(a->children().size() >= 2 && m_b_split_vec.size());
nex* f;
a->simplify(&f, m_lt);
a->simplify(&f, m_lt, m_mk_scalar);
if (m_b_split_vec.size() == 1) {
b = m_b_split_vec[0];
@ -488,7 +490,7 @@ public:
a->children()[j] = normalize(a->children()[j]);
}
nex *r;
a->simplify(&r, m_lt);
a->simplify(&r, m_lt, m_mk_scalar);
return r;
}

View file

@ -22,15 +22,8 @@
namespace nla {
bool ignored_child(nex* e, expr_type t) {
switch(t) {
case expr_type::MUL:
return e->is_scalar() && to_scalar(e)->value().is_one();
case expr_type::SUM:
return e->is_scalar() && to_scalar(e)->value().is_zero();
default: return false;
}
return false;
bool is_zero_scalar(nex* e) {
return e->is_scalar() && to_scalar(e)->value().is_zero();
}
void mul_to_powers(vector<nex_pow>& children, nex_lt lt) {
@ -54,15 +47,50 @@ void mul_to_powers(vector<nex_pow>& children, nex_lt lt) {
});
}
void promote_children_of_sum(ptr_vector<nex> & children, nex_lt lt ) {
rational extract_coeff(const nex_mul* m) {
const nex* e = m->children().begin()->e();
if (e->is_scalar())
return to_scalar(e)->value();
return rational(1);
}
bool sum_simplify_lt(const nex_mul* a, const nex_mul* b, const nex_lt& lt) {
NOT_IMPLEMENTED_YET();
}
// a + 3bc + 2bc => a + 5bc
void sort_join_sum(ptr_vector<nex> & children, nex_lt& lt, std::function<nex_scalar*()> mk_scalar) {
ptr_vector<nex> non_muls;
std::map<nex_mul*, rational, std::function<bool(const nex_mul *a , const nex_mul *b)>>
m([lt](const nex_mul *a , const nex_mul *b) { return sum_simplify_lt(a, b, lt); });
for (nex* e : children) {
SASSERT(e->is_simplified(lt));
if (!e->is_mul()) {
non_muls.push_back(e);
} else {
nex_mul * em = to_mul(e);
rational r = extract_coeff(em);
auto it = m.find(em);
if (it == m.end()) {
m[em] = r;
} else {
it->second += r;
}
}
}
NOT_IMPLEMENTED_YET();
}
void simplify_children_of_sum(ptr_vector<nex> & children, nex_lt lt, std::function<nex_scalar*()> mk_scalar ) {
ptr_vector<nex> to_promote;
int skipped = 0;
for(unsigned j = 0; j < children.size(); j++) {
nex** e = &(children[j]);
(*e)->simplify(e, lt);
(*e)->simplify(e, lt, mk_scalar);
if ((*e)->is_sum()) {
to_promote.push_back(*e);
} else if (ignored_child(*e, expr_type::SUM)) {
} else if (is_zero_scalar(*e)) {
skipped ++;
continue;
} else {
@ -77,13 +105,15 @@ void promote_children_of_sum(ptr_vector<nex> & children, nex_lt lt ) {
for (nex *e : to_promote) {
for (nex *ee : *(to_sum(e)->children_ptr())) {
if (!ignored_child(ee, expr_type::SUM))
if (!is_zero_scalar(ee))
children.push_back(ee);
}
}
}
sort_join_sum(children, lt, mk_scalar);
}
bool eat_scalar(nex_scalar *& r, nex_pow& p) {
bool eat_scalar_pow(nex_scalar *& r, nex_pow& p) {
if (!p.e()->is_scalar())
return false;
nex_scalar *pe = to_scalar(p.e());
@ -96,18 +126,18 @@ bool eat_scalar(nex_scalar *& r, nex_pow& p) {
return true;
}
void simplify_children_of_mul(vector<nex_pow> & children, nex_lt lt) {
void simplify_children_of_mul(vector<nex_pow> & children, nex_lt lt, std::function<nex_scalar*()> mk_scalar) {
nex_scalar* r = nullptr;
TRACE("nla_cn_details", print_vector(children, tout););
vector<nex_pow> to_promote;
int skipped = 0;
for(unsigned j = 0; j < children.size(); j++) {
nex_pow& p = children[j];
if (eat_scalar(r, p)) {
if (eat_scalar_pow(r, p)) {
skipped++;
continue;
}
(p.e())->simplify(p.ee(), lt);
(p.e())->simplify(p.ee(), lt, mk_scalar );
if ((p.e())->is_mul()) {
to_promote.push_back(p);
} else {
@ -122,7 +152,7 @@ void simplify_children_of_mul(vector<nex_pow> & children, nex_lt lt) {
for (nex_pow & p : to_promote) {
for (nex_pow& pp : to_mul(p.e())->children()) {
if (!eat_scalar(r, pp))
if (!eat_scalar_pow(r, pp))
children.push_back(nex_pow(pp.e(), pp.pow() * p.pow()));
}
}
@ -133,7 +163,36 @@ void simplify_children_of_mul(vector<nex_pow> & children, nex_lt lt) {
mul_to_powers(children, lt);
TRACE("nla_cn_details", print_vector(children, tout););
TRACE("nla_cn_details", print_vector(children, tout););
}
bool less_than_nex(const nex* a, const nex* b, lt_on_vars lt) {
int r = (int)(a->type()) - (int)(b->type());
if (r) {
return r < 0;
}
SASSERT(a->type() == b->type());
switch (a->type()) {
case expr_type::VAR: {
return lt(to_var(a)->var() , to_var(b)->var());
}
case expr_type::SCALAR: {
return to_scalar(a)->value() < to_scalar(b)->value();
}
case expr_type::MUL: {
NOT_IMPLEMENTED_YET();
return false; // to_mul(a)->children() < to_mul(b)->children();
}
case expr_type::SUM: {
NOT_IMPLEMENTED_YET();
return false; //to_sum(a)->children() < to_sum(b)->children();
}
default:
SASSERT(false);
return false;
}
return false;
}
}

View file

@ -52,6 +52,7 @@ inline std::ostream & operator<<(std::ostream& out, expr_type t) {
class nex;
bool less_than_nex_standard(const nex* a, const nex* b);
class nex_scalar;
// This is the class of non-linear expressions
class nex {
public:
@ -78,8 +79,8 @@ public:
virtual bool contains(lpvar j) const { return false; }
virtual int get_degree() const = 0;
// simplifies the expression and also assigns the address of "this" to *e
virtual void simplify(nex** e, nex_lt) { *e = this; }
void simplify(nex** e) { return simplify(e, less_than_nex_standard); }
virtual void simplify(nex** e, nex_lt, std::function<nex_scalar*()>) = 0;
void simplify(nex** e, std::function<nex_scalar*()> mk_scalar) { return simplify(e, less_than_nex_standard, mk_scalar); }
virtual bool is_simplified(nex_lt) const {
return true;
}
@ -115,6 +116,7 @@ public:
bool contains(lpvar j) const { return j == m_j; }
int get_degree() const { return 1; }
bool virtual is_linear() const { return true; }
void simplify(nex** e, nex_lt, std::function<nex_scalar*()>) {*e = this;}
};
class nex_scalar : public nex {
@ -132,6 +134,7 @@ public:
int get_degree() const { return 0; }
bool is_linear() const { return true; }
void simplify(nex** e, nex_lt, std::function<nex_scalar*()>) {*e = this;}
};
@ -139,9 +142,9 @@ const nex_scalar * to_scalar(const nex* a);
class nex_sum;
const nex_sum* to_sum(const nex*a);
void promote_children_of_sum(ptr_vector<nex> & children, nex_lt);
void simplify_children_of_sum(ptr_vector<nex> & children, nex_lt, std::function<nex_scalar*()>);
class nex_pow;
void simplify_children_of_mul(vector<nex_pow> & children, nex_lt);
void simplify_children_of_mul(vector<nex_pow> & children, nex_lt, std::function<nex_scalar*()>);
class nex_pow {
nex* m_e;
@ -238,12 +241,12 @@ public:
return degree;
}
// the second argument is the comparison less than operator
void simplify(nex **e, nex_lt lt) {
void simplify(nex **e, nex_lt lt, std::function<nex_scalar*()> mk_scalar) {
TRACE("nla_cn_details", tout << *this << "\n";);
TRACE("nla_cn_details", tout << "**e = " << **e << "\n";);
*e = this;
TRACE("nla_cn_details", tout << *this << "\n";);
simplify_children_of_mul(m_children, lt);
simplify_children_of_mul(m_children, lt, mk_scalar);
if (size() == 1 && m_children[0].pow() == 1)
*e = m_children[0].e();
TRACE("nla_cn_details", tout << *this << "\n";);
@ -361,9 +364,9 @@ public:
return out;
}
void simplify(nex **e, nex_lt lt ) {
void simplify(nex **e, nex_lt lt, std::function<nex_scalar*()> mk_scalar) {
*e = this;
promote_children_of_sum(m_children, lt);
simplify_children_of_sum(m_children, lt, mk_scalar);
if (size() == 1)
*e = m_children[0];
}
@ -444,37 +447,11 @@ inline std::ostream& operator<<(std::ostream& out, const nex& e ) {
}
inline bool less_than_nex(const nex* a, const nex* b, lt_on_vars lt) {
int r = (int)(a->type()) - (int)(b->type());
if (r) {
return r < 0;
}
// here a and b have the same type
switch (a->type()) {
case expr_type::VAR: {
return lt(to_var(a)->var() , to_var(b)->var());
}
case expr_type::SCALAR: {
return to_scalar(a)->value() < to_scalar(b)->value();
}
case expr_type::MUL: {
NOT_IMPLEMENTED_YET();
return false; // to_mul(a)->children() < to_mul(b)->children();
}
case expr_type::SUM: {
NOT_IMPLEMENTED_YET();
return false; //to_sum(a)->children() < to_sum(b)->children();
}
default:
SASSERT(false);
return false;
}
return false;
}
bool less_than_nex(const nex* a, const nex* b, lt_on_vars lt);
inline bool less_than_nex_standard(const nex* a, const nex* b) {
return less_than_nex(a, b, [](lpvar j, lpvar k) { return j < k; });
lt_on_vars lt = [](lpvar j, lpvar k) { return j < k; };
return less_than_nex(a, b, lt);
}
#if Z3DEBUG

View file

@ -170,7 +170,8 @@ private:
}
bool less_than_on_expr(const nex* a, const nex* b) const {
return less_than_nex(a, b, [this](lpvar j, lpvar k) {return less_than_on_vars(j, k);});
lt_on_vars lt = [this](lpvar j, lpvar k) {return less_than_on_vars(j, k);};
return less_than_nex(a, b, lt);
}

View file

@ -85,26 +85,31 @@ void test_simplify() {
);
enable_trace("nla_cn");
enable_trace("nla_cn_details");
auto & creator = cn.get_nex_creator();
nex_var* a = creator.mk_var(0);
nex_var* b = creator.mk_var(1);
nex_var* c = creator.mk_var(2);
auto m = creator.mk_mul(); m->add_child_in_power(c, 2);
nex_creator & r = cn.get_nex_creator();
nex_var* a = r.mk_var(0);
nex_var* b = r.mk_var(1);
nex_var* c = r.mk_var(2);
auto m = r.mk_mul(); m->add_child_in_power(c, 2);
TRACE("nla_cn", tout << "m = " << *m << "\n";);
auto n = creator.mk_mul(a);
auto n = r.mk_mul(a);
n->add_child_in_power(b, 7);
n->add_child(creator.mk_scalar(rational(3)));
n->add_child_in_power(creator.mk_scalar(rational(4)), 2);
n->add_child(creator.mk_scalar(rational(1)));
n->add_child(r.mk_scalar(rational(3)));
n->add_child_in_power(r.mk_scalar(rational(4)), 2);
n->add_child(r.mk_scalar(rational(1)));
TRACE("nla_cn", tout << "n = " << *n << "\n";);
m->add_child_in_power(n, 3);
n->add_child_in_power(creator.mk_scalar(rational(1, 3)), 2);
n->add_child_in_power(r.mk_scalar(rational(1, 3)), 2);
TRACE("nla_cn", tout << "m = " << *m << "\n";);
nex * e = creator.mk_sum(a, creator.mk_sum(b, m));
nex * e = r.mk_sum(a, r.mk_sum(b, m));
TRACE("nla_cn", tout << "e = " << *e << "\n";);
e->simplify(&e);
std::function<nex_scalar*()> mks = [&r] {return r.mk_scalar(rational(1)); };
e->simplify(&e, mks);
TRACE("nla_cn", tout << "simplified e = " << *e << "\n";);
nex * l = r.mk_sum(e, r.mk_mul(r.mk_scalar(rational(3)), r.clone(e)));
TRACE("nla_cn", tout << "sum l = " << *l << "\n";);
l->simplify(&l, mks);
TRACE("nla_cn", tout << "simplified sum l = " << *l << "\n";);
}
void test_cn() {
@ -142,7 +147,7 @@ void test_cn() {
nex* _6aad = cn.get_nex_creator().mk_mul(cn.get_nex_creator().mk_scalar(rational(6)), a, a, d);
#ifdef Z3DEBUG
nex * clone = cn.get_nex_creator().clone(cn.get_nex_creator().mk_sum(_6aad, abcd, aaccd, add, eae, eac, ed));
clone->simplify(&clone);
clone->simplify(&clone,[&cn] {return cn.get_nex_creator().mk_scalar(rational(1));});
SASSERT(clone->is_simplified());
TRACE("nla_cn", tout << "clone = " << *clone << "\n";);
#endif