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use nonse based seed for transition characters

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-06-24 12:07:29 -07:00
parent b0633ecc86
commit c0fbb31379
3 changed files with 28 additions and 19 deletions

View file

@ -413,16 +413,22 @@ namespace smt {
}
void seq_regex::propagate_eq(expr* r1, expr* r2) {
sort* seq_sort = nullptr;
VERIFY(u().is_re(r1, seq_sort));
expr_ref r = symmetric_diff(r1, r2);
expr_ref emp(re().mk_empty(m.get_sort(r)), m);
expr_ref is_empty = sk().mk_is_empty(r, emp);
expr_ref n(m.mk_fresh_const("re.char", seq_sort), m);
expr_ref is_empty = sk().mk_is_empty(r, emp, n);
th.add_axiom(~th.mk_eq(r1, r2, false), th.mk_literal(is_empty));
}
void seq_regex::propagate_ne(expr* r1, expr* r2) {
sort* seq_sort = nullptr;
VERIFY(u().is_re(r1, seq_sort));
expr_ref r = symmetric_diff(r1, r2);
expr_ref emp(re().mk_empty(m.get_sort(r)), m);
expr_ref is_non_empty = sk().mk_is_non_empty(r, emp);
expr_ref n(m.mk_fresh_const("re.char", seq_sort), m);
expr_ref is_non_empty = sk().mk_is_non_empty(r, emp, n);
th.add_axiom(th.mk_eq(r1, r2, false), th.mk_literal(is_non_empty));
}
@ -444,14 +450,14 @@ namespace smt {
*
*/
void seq_regex::propagate_is_non_empty(literal lit) {
expr* e = ctx.bool_var2expr(lit.var()), *r = nullptr, *u = nullptr;
VERIFY(sk().is_is_non_empty(e, r, u));
expr* e = ctx.bool_var2expr(lit.var()), *r = nullptr, *u = nullptr, *n = nullptr;
VERIFY(sk().is_is_non_empty(e, r, u, n));
expr_ref is_nullable = seq_rw().is_nullable(r);
rewrite(is_nullable);
if (m.is_true(is_nullable))
return;
literal null_lit = th.mk_literal(is_nullable);
expr_ref hd = mk_first(r);
expr_ref hd = mk_first(r, n);
expr_ref d(m);
d = derivative_wrapper(hd, r);
literal_vector lits;
@ -468,7 +474,7 @@ namespace smt {
rewrite(cond);
if (m.is_false(cond))
continue;
expr_ref next_non_empty = sk().mk_is_non_empty(p.second, re().mk_union(u, r));
expr_ref next_non_empty = sk().mk_is_non_empty(p.second, re().mk_union(u, p.second), n);
if (!m.is_true(cond))
next_non_empty = m.mk_and(cond, next_non_empty);
lits.push_back(th.mk_literal(next_non_empty));
@ -499,8 +505,8 @@ namespace smt {
is_empty(r, u) is true if r is a member of u
*/
void seq_regex::propagate_is_empty(literal lit) {
expr* e = ctx.bool_var2expr(lit.var()), *r = nullptr, *u = nullptr;
VERIFY(sk().is_is_empty(e, r, u));
expr* e = ctx.bool_var2expr(lit.var()), *r = nullptr, *u = nullptr, *n = nullptr;
VERIFY(sk().is_is_empty(e, r, u, n));
expr_ref is_nullable = seq_rw().is_nullable(r);
rewrite(is_nullable);
if (m.is_true(is_nullable)) {
@ -508,7 +514,7 @@ namespace smt {
return;
}
th.add_axiom(~lit, ~th.mk_literal(is_nullable));
expr_ref hd = mk_first(r);
expr_ref hd = mk_first(r, n);
expr_ref d(m);
d = derivative_wrapper(hd, r);
literal_vector lits;
@ -528,16 +534,17 @@ namespace smt {
expr_ref ncond(mk_not(m, cond), m);
lits.push_back(th.mk_literal(mk_forall(m, hd, ncond)));
}
expr_ref is_empty1 = sk().mk_is_empty(p.second, re().mk_union(u, r));
expr_ref is_empty1 = sk().mk_is_empty(p.second, re().mk_union(u, r), n);
lits.push_back(th.mk_literal(is_empty1));
th.add_axiom(lits);
}
}
expr_ref seq_regex::mk_first(expr* r) {
expr_ref seq_regex::mk_first(expr* r, expr* n) {
sort* elem_sort = nullptr, *seq_sort = nullptr;
VERIFY(u().is_re(r, seq_sort));
VERIFY(u().is_seq(seq_sort, elem_sort));
return expr_ref(m.mk_fresh_const("re.first", elem_sort), m);
sort* domain[2] = { m.get_sort(n), a().mk_int() };
return sk().mk("re.first", n, a().mk_int(r->get_id()), elem_sort);
}
}

View file

@ -71,7 +71,7 @@ namespace smt {
bool propagate_derivative(literal lit, expr* e, expr* s, expr* i, unsigned idx, expr* r, literal& trigger);
expr_ref mk_first(expr* r);
expr_ref mk_first(expr* r, expr* n);
expr_ref unroll_non_empty(expr* r, expr_mark& seen, unsigned depth);

View file

@ -48,11 +48,13 @@ namespace smt {
expr_ref mk(symbol const& s, sort* range) { return mk(s, nullptr, nullptr, nullptr, nullptr, range); }
expr_ref mk(symbol const& s, expr* e, sort* range) { return mk(s, e, nullptr, nullptr, nullptr, range); }
expr_ref mk(symbol const& s, expr* e1, expr* e2, sort* range) { return mk(s, e1, e2, nullptr, nullptr, range); }
expr_ref mk(symbol const& s, expr* e1, expr* e2, expr* e3, sort* range) { return mk(s, e1, e2, e3, nullptr, range); }
expr_ref mk(symbol const& s, expr* e1, expr* e2 = nullptr, expr* e3 = nullptr, expr* e4 = nullptr, sort* range = nullptr);
expr_ref mk(char const* s, sort* range) { return mk(s, nullptr, nullptr, nullptr, nullptr, range); }
expr_ref mk(char const* s, expr* e, sort* range) { return mk(s, e, nullptr, nullptr, nullptr, range); }
expr_ref mk(char const* s, expr* e1, expr* e2, sort* range) { return mk(s, e1, e2, nullptr, nullptr, range); }
expr_ref mk(char const* s, expr* e1, expr* e2, expr* e3, sort* range) { return mk(s, e1, e2, e3, nullptr, range); }
expr_ref mk(char const* s , expr* e1, expr* e2 = nullptr, expr* e3 = nullptr, expr* e4 = nullptr, sort* range = nullptr) {
return mk(symbol(s), e1, e2, e3, e4, range);
}
@ -70,8 +72,8 @@ namespace smt {
}
expr_ref mk_accept(expr_ref_vector const& args) { return expr_ref(seq.mk_skolem(m_accept, args.size(), args.c_ptr(), m.mk_bool_sort()), m); }
expr_ref mk_accept(expr* s, expr* i, expr* r) { return mk(m_accept, s, i, r, nullptr, m.mk_bool_sort()); }
expr_ref mk_is_non_empty(expr* r, expr* u) { return mk(m_is_non_empty, r, u, m.mk_bool_sort()); }
expr_ref mk_is_empty(expr* r, expr* u) { return mk(m_is_empty, r, u, m.mk_bool_sort()); }
expr_ref mk_is_non_empty(expr* r, expr* u, expr* n) { return mk(m_is_non_empty, r, u, n, m.mk_bool_sort()); }
expr_ref mk_is_empty(expr* r, expr* u, expr* n) { return mk(m_is_empty, r, u, n, m.mk_bool_sort()); }
expr_ref mk_indexof_left(expr* t, expr* s, expr* offset = nullptr) { return mk(m_indexof_left, t, s, offset); }
expr_ref mk_indexof_right(expr* t, expr* s, expr* offset = nullptr) { return mk(m_indexof_right, t, s, offset); }
@ -135,11 +137,11 @@ namespace smt {
bool is_length_limit(expr* p, unsigned& lim, expr*& s) const;
bool is_is_empty(expr* e) const { return is_skolem(m_is_empty, e); }
bool is_is_non_empty(expr* e) const { return is_skolem(m_is_non_empty, e); }
bool is_is_empty(expr* e, expr*& r, expr*& u) const {
return is_skolem(m_is_empty, e) && (r = to_app(e)->get_arg(0), u = to_app(e)->get_arg(1), true);
bool is_is_empty(expr* e, expr*& r, expr*& u, expr*& n) const {
return is_skolem(m_is_empty, e) && (r = to_app(e)->get_arg(0), u = to_app(e)->get_arg(1), n = to_app(e)->get_arg(2), true);
}
bool is_is_non_empty(expr* e, expr*& r, expr*& u) const {
return is_skolem(m_is_non_empty, e) && (r = to_app(e)->get_arg(0), u = to_app(e)->get_arg(1), true);
bool is_is_non_empty(expr* e, expr*& r, expr*& u, expr*& n) const {
return is_skolem(m_is_non_empty, e) && (r = to_app(e)->get_arg(0), u = to_app(e)->get_arg(1), n = to_app(e)->get_arg(2), true);
}
void decompose(expr* e, expr_ref& head, expr_ref& tail);