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feat(library/blast/forward/ematch): add support for multi-patterns

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This commit is contained in:
Leonardo de Moura 2015-11-30 11:19:08 -07:00
parent 9260be01b2
commit 32ad59adc1
2 changed files with 63 additions and 40 deletions
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94
src/library/blast/forward/ematch.cpp
View file

@ -159,6 +159,27 @@ struct ematch_fn {
return m_ctx->is_def_eq(p, t);
}
bool match_args(state & s, name const & R, buffer<expr> const & p_args, expr const & t) {
optional<ext_congr_lemma> cg_lemma = mk_ext_congr_lemma(R, get_app_fn(t), p_args.size());
if (!cg_lemma)
return false;
buffer<expr> t_args;
get_app_args(t, t_args);
if (p_args.size() != t_args.size())
return false;
auto const * r_names = &cg_lemma->m_rel_names;
for (unsigned i = 0; i < p_args.size(); i++) {
lean_assert(*r_names);
if (auto Rc = head(*r_names)) {
s = cons(entry(*Rc, Match, p_args[i], t_args[i]), s);
} else {
s = cons(entry(get_eq_name(), DefEqOnly, p_args[i], t_args[i]), s);
}
r_names = &tail(*r_names);
}
return true;
}
bool process_match(name const & R, expr const & p, expr const & t) {
if (!is_app(p))
return is_eqv(R, p, t);
@ -180,30 +201,14 @@ struct ematch_fn {
} while (it != t);
if (candidates.empty())
return false;
optional<ext_congr_lemma> lemma = mk_ext_congr_lemma(R, t_fn, p_args.size());
if (!lemma)
return false;
buffer<state> new_states;
for (expr const & c : candidates) {
buffer<expr> c_args;
get_app_args(c, c_args);
lean_assert(c_args.size() == p_args.size());
state new_state = m_state;
auto const * r_names = &lemma->m_rel_names;
for (unsigned i = 0; i < p_args.size(); i++) {
lean_assert(*r_names);
if (auto Rc = head(*r_names)) {
new_state = cons(entry(*Rc, Match, p_args[i], c_args[i]), new_state);
} else {
new_state = cons(entry(get_eq_name(), DefEqOnly, p_args[i], c_args[i]), new_state);
}
r_names = &tail(*r_names);
if (match_args(new_state, R, p_args, c)) {
new_states.push_back(new_state);
}
new_states.push_back(new_state);
}
lean_assert(candidates.size() == new_states.size());
if (candidates.size() == 1) {
if (new_states.size() == 1) {
m_state = new_states[0];
return true;
} else {
@ -216,9 +221,34 @@ struct ematch_fn {
}
}
bool process_continue(expr const &) {
// TODO(Leo):
return false;
bool process_continue(name const & R, expr const & p) {
buffer<expr> p_args;
expr const & f = get_app_args(p, p_args);
buffer<state> new_states;
if (auto s = m_ext.m_apps.find(head_index(f))) {
s->for_each([&](expr const & t) {
if (m_cc.is_congr_root(R, t)) {
state new_state = m_state;
if (match_args(new_state, R, p_args, t))
new_states.push_back(new_state);
}
});
if (new_states.empty()) {
return false;
} else if (new_states.size() == 1) {
m_state = new_states[0];
return true;
} else {
m_state = new_states.back();
new_states.pop_back();
choice c = to_list(new_states);
m_choice_stack.push_back(c);
m_ctx->push();
return true;
}
} else {
return false;
}
}
bool process_next() {
@ -233,7 +263,7 @@ struct ematch_fn {
case Match:
return process_match(R, p, t);
case Continue:
return process_continue(p);
return process_continue(R, p);
}
lean_unreachable();
}
@ -316,24 +346,8 @@ struct ematch_fn {
}
m_choice_stack.clear();
m_state = s;
optional<ext_congr_lemma> cg_lemma = mk_ext_congr_lemma(R, get_app_fn(t), p0_args.size());
if (!cg_lemma)
if (!match_args(m_state, R, p0_args, t))
return;
buffer<expr> t_args;
get_app_args(t, t_args);
if (p0_args.size() != t_args.size())
return;
auto const * r_names = &cg_lemma->m_rel_names;
for (unsigned i = 0; i < p0_args.size(); i++) {
lean_assert(*r_names);
if (auto Rc = head(*r_names)) {
m_state = cons(entry(*Rc, Match, p0_args[i], t_args[i]), m_state);
} else {
m_state = cons(entry(get_eq_name(), DefEqOnly, p0_args[i], t_args[i]), m_state);
}
r_names = &tail(*r_names);
}
search(lemma);
}
});

9
tests/lean/run/blast_ematch5.lean Normal file
View file

@ -0,0 +1,9 @@
constant subt : nat → nat → Prop
lemma subt_trans [forward] {a b c : nat} : subt a b → subt b c → subt a c :=
sorry
set_option blast.ematch true
example (a b c d : nat) : subt a b → subt b c → subt c d → subt a d :=
by blast