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add rule unfolding transformation

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2012-10-15 15:34:29 -07:00
parent 2c24f25050
commit d16db63e56
13 changed files with 160 additions and 138 deletions
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120
lib/pdr_generalizers.cpp
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@ -683,123 +683,3 @@ namespace pdr {
}
};
#if 0
void model_farkas_generalizer::extract_eqs(expr_ref_vector const& lits, eqs& eqs) {
expr* e;
rational vl;
bool is_int;
for (unsigned i = 0; i < lits.size(); ++i) {
if (is_eq(lits[i], e, vl, is_int)) {
eqs.push_back(std::make_pair(e, vl));
}
}
}
void model_farkas_generalizer::solve_eqs(expr_ref& A, expr_ref_vector& other, eqs const& o_eqs) {
if (o_eqs.empty()) {
return;
}
expr_substitution sub(m);
scoped_ptr<expr_replacer> rep = mk_default_expr_replacer(m);
rep->set_substitution(&sub);
expr* e1;
rational vl1;
bool is_int;
for (unsigned i = 0; i < other.size(); ++i) {
if (is_eq(other[i].get(), e1, vl1, is_int)) {
unsigned k = m_random(o_eqs.size());
for (unsigned j = 0; j < o_eqs.size(); ++j) {
unsigned l = (j+k)%o_eqs.size();
expr* e2 = o_eqs[l].first;
if (m.get_sort(e1) == m.get_sort(e2)) {
sub.insert(e1, mk_offset(e2, vl1-o_eqs[l].second));
other[i] = m.mk_true();
break;
}
}
}
}
(*rep)(A);
other.push_back(A);
A = m.mk_and(other.size(), other.c_ptr());
}
expr* model_farkas_generalizer::mk_offset(expr* e, rational const& r) {
if (r.is_zero()) {
return e;
}
else {
return a.mk_add(e, a.mk_numeral(r, a.is_int(e)));
}
}
void model_farkas_generalizer::connect_vars(ptr_vector<expr>& vars, vector<rational>& vals, expr_ref_vector& lits) {
switch(vars.size()) {
case 0:
break;
case 1:
lits.push_back(m.mk_eq(vars[0], a.mk_numeral(vals[0], a.is_int(vars[0]))));
break;
case 2:
lits.push_back(m.mk_eq(vars[0], a.mk_numeral(vals[0], a.is_int(vars[0]))));
lits.push_back(m.mk_eq(vars[0], mk_offset(vars[1], vals[0]-vals[1])));
break;
default: {
ptr_vector<expr> new_vars;
vector<rational> new_vals;
unsigned j, i = m_random(vars.size());
new_vars.push_back(vars[i]);
new_vals.push_back(vals[i]);
lits.push_back(m.mk_eq(vars[i], a.mk_numeral(vals[i], a.is_int(vars[i]))));
vars.erase(vars.begin() + i);
vals.erase(vals.begin() + i);
while (!vars.empty()) {
i = m_random(vars.size());
j = m_random(new_vars.size());
lits.push_back(m.mk_eq(vars[i], mk_offset(new_vars[j], vals[i]-new_vals[j])));
new_vars.push_back(vars[i]);
new_vals.push_back(vals[i]);
vars.erase(vars.begin() + i);
vals.erase(vals.begin() + i);
}
break;
}
}
}
bool model_farkas_generalizer::is_eq(expr* e, expr*& r, rational& vl, bool& is_int) {
expr* r2 = 0;
return
(m.is_eq(e, r, r2) && a.is_numeral(r2, vl, is_int)) ||
(m.is_eq(e, r2, r) && a.is_numeral(r2, vl, is_int));
}
void model_farkas_generalizer::relativize(expr_ref_vector& literals) {
ast_manager& m = literals.get_manager();
ptr_vector<expr> ints, reals;
vector<rational> int_vals, real_vals;
expr* e;
rational vl;
bool is_int;
for (unsigned i = 0; i < literals.size(); ) {
if (is_eq(literals[i].get(), e, vl, is_int)) {
(is_int?ints:reals).push_back(e);
(is_int?int_vals:real_vals).push_back(vl);
literals[i] = literals.back();
literals.pop_back();
}
else {
++i;
}
}
connect_vars(ints, int_vals, literals);
connect_vars(reals, real_vals, literals);
}
#endif