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mirror of https://github.com/Z3Prover/z3 synced 2025-04-08 18:31:49 +00:00
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-06-07 12:52:09 -07:00
parent cfed69caae
commit d2a12f6db5
3 changed files with 101 additions and 20 deletions

View file

@ -2758,7 +2758,6 @@ br_status seq_rewriter::mk_str_in_regexp(expr* a, expr* b, expr_ref& result) {
return BR_REWRITE_FULL;
}
#if 0
if (get_re_head_tail(b, hd, tl)) {
SASSERT(re().min_length(hd) == re().max_length(hd));
expr_ref len_hd(m_autil.mk_int(re().min_length(hd)), m());
@ -2779,7 +2778,6 @@ br_status seq_rewriter::mk_str_in_regexp(expr* a, expr* b, expr_ref& result) {
re().mk_in_re(str().mk_substr(a, len_hd, len_tl), tl));
return BR_REWRITE_FULL;
}
#endif
if (false && rewrite_contains_pattern(a, b, result))
return BR_REWRITE_FULL;
@ -2859,6 +2857,50 @@ br_status seq_rewriter::mk_re_concat(expr* a, expr* b, expr_ref& result) {
}
return BR_FAILED;
}
bool seq_rewriter::are_complements(expr* r1, expr* r2) const {
expr* r = nullptr;
if (re().is_complement(r1, r) && r == r2)
return true;
if (re().is_complement(r2, r) && r == r1)
return true;
return false;
}
/*
* basic subset checker.
*/
bool seq_rewriter::is_subset(expr* r1, expr* r2) const {
// return false;
expr* ra1 = nullptr, *ra2 = nullptr, *ra3 = nullptr;
expr* rb1 = nullptr, *rb2 = nullptr, *rb3 = nullptr;
if (re().is_complement(r1, ra1) &&
re().is_complement(r2, rb1)) {
return is_subset(rb1, ra1);
}
auto is_concat = [&](expr* r, expr*& a, expr*& b, expr*& c) {
return re().is_concat(r, a, b) && re().is_concat(b, b, c);
};
while (true) {
if (r1 == r2)
return true;
if (re().is_full_seq(r2))
return true;
if (is_concat(r1, ra1, ra2, ra3) &&
is_concat(r2, rb1, rb2, rb3) && ra1 == rb1 && ra2 == rb2) {
r1 = ra3;
r2 = rb3;
continue;
}
if (re().is_concat(r1, ra1, ra2) &&
re().is_concat(r2, rb1, rb2) && re().is_full_seq(rb1)) {
r1 = ra2;
continue;
}
return false;
}
}
/*
(a + a) = a
(a + eps) = a
@ -2893,7 +2935,12 @@ br_status seq_rewriter::mk_re_union(expr* a, expr* b, expr_ref& result) {
result = b;
return BR_DONE;
}
expr* ac = nullptr, *bc = nullptr;
auto mk_full = [&]() { return re().mk_full_seq(m().get_sort(a)); };
if (are_complements(a, b)) {
result = mk_full();
return BR_DONE;
}
expr* a1 = nullptr, *a2 = nullptr;
expr* b1 = nullptr, *b2 = nullptr;
// ensure union is right-associative
@ -2902,18 +2949,17 @@ br_status seq_rewriter::mk_re_union(expr* a, expr* b, expr_ref& result) {
result = re().mk_union(a1, re().mk_union(a2, b));
return BR_REWRITE2;
}
auto mk_full = [&]() { return re().mk_full_seq(m().get_sort(a)); };
auto get_id = [&](expr* e) { re().is_complement(e, e); return e->get_id(); };
if (re().is_union(b, b1, b2)) {
if (a == b1) {
if (is_subset(a, b1)) {
result = b;
return BR_DONE;
}
if (re().is_complement(a, ac) && b1 == ac) {
result = mk_full();
return BR_DONE;
if (is_subset(b1, a)) {
result = re().mk_union(a, b2);
return BR_REWRITE1;
}
if (re().is_complement(b1, bc) && a == bc) {
if (are_complements(a, b1)) {
result = mk_full();
return BR_DONE;
}
@ -2922,6 +2968,20 @@ br_status seq_rewriter::mk_re_union(expr* a, expr* b, expr_ref& result) {
return BR_REWRITE2;
}
}
else {
if (get_id(a) > get_id(b)) {
result = re().mk_union(b, a);
return BR_DONE;
}
if (is_subset(a, b)) {
result = b;
return BR_DONE;
}
if (is_subset(b, a)) {
result = a;
return BR_DONE;
}
}
return BR_FAILED;
}
@ -2978,7 +3038,11 @@ br_status seq_rewriter::mk_re_inter(expr* a, expr* b, expr_ref& result) {
result = a;
return BR_DONE;
}
expr* ac = nullptr, *bc = nullptr;
auto mk_empty = [&]() { return re().mk_empty(m().get_sort(a)); };
if (are_complements(a, b)) {
result = mk_empty();
return BR_DONE;
}
expr* a1 = nullptr, *a2 = nullptr;
expr* b1 = nullptr, *b2 = nullptr;
@ -2988,18 +3052,17 @@ br_status seq_rewriter::mk_re_inter(expr* a, expr* b, expr_ref& result) {
result = re().mk_inter(a1, re().mk_inter(a2, b));
return BR_REWRITE2;
}
auto mk_empty = [&]() { return re().mk_empty(m().get_sort(a)); };
auto get_id = [&](expr* e) { re().is_complement(e, e); return e->get_id(); };
if (re().is_intersection(b, b1, b2)) {
if (a == b1) {
if (is_subset(b1, a)) {
result = b;
return BR_DONE;
}
if (re().is_complement(a, ac) && b1 == ac) {
result = mk_empty();
return BR_DONE;
if (is_subset(a, b1)) {
result = re().mk_inter(a, b2);
return BR_REWRITE1;
}
if (re().is_complement(b1, bc) && a == bc) {
if (are_complements(a, b1)) {
result = mk_empty();
return BR_DONE;
}
@ -3008,10 +3071,19 @@ br_status seq_rewriter::mk_re_inter(expr* a, expr* b, expr_ref& result) {
return BR_REWRITE2;
}
}
if ((re().is_complement(a, ac) && ac == b) ||
(re().is_complement(b, bc) && bc == a)) {
result = mk_empty();
return BR_DONE;
else {
if (get_id(a) > get_id(b)) {
result = re().mk_inter(b, a);
return BR_DONE;
}
if (is_subset(a, b)) {
result = a;
return BR_DONE;
}
if (is_subset(b, a)) {
result = b;
return BR_DONE;
}
}
if (re().is_to_re(b))
std::swap(a, b);

View file

@ -189,6 +189,9 @@ class seq_rewriter {
expr_ref mk_derivative(expr* ele, expr* r);
expr_ref mk_derivative_rec(expr* ele, expr* r);
bool are_complements(expr* r1, expr* r2) const;
bool is_subset(expr* r1, expr* r2) const;
br_status mk_seq_unit(expr* e, expr_ref& result);
br_status mk_seq_concat(expr* a, expr* b, expr_ref& result);
br_status mk_seq_length(expr* a, expr_ref& result);

View file

@ -223,7 +223,12 @@ namespace smt {
expr_ref d(m);
expr_ref head = th.mk_nth(s, i);
d = re().mk_derivative(m.mk_var(0, m.get_sort(head)), r);
// timer tm;
rewrite(d);
// std::cout << d->get_id() << " " << tm.get_seconds() << "\n";
// if (tm.get_seconds() > 1)
// std::cout << d << "\n";
// std::cout.flush();
literal_vector conds;
conds.push_back(~lit);
conds.push_back(th.m_ax.mk_le(th.mk_len(s), idx));
@ -297,6 +302,7 @@ namespace smt {
* within the same Regex.
*/
bool seq_regex::coallesce_in_re(literal lit) {
return false;
expr* s = nullptr, *r = nullptr;
expr* e = ctx.bool_var2expr(lit.var());
VERIFY(str().is_in_re(e, s, r));