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fix(library/tactic/rewrite_tactic): adjust the behavior of class resolution in rewriter

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The solution is not very satisfactory. I should investigate it more.
This commit is contained in:
Leonardo de Moura 2015-02-05 19:08:47 -08:00
parent 96c161a659
commit e17ba27596
2 changed files with 21 additions and 7 deletions
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10
src/library/tactic/rewrite_tactic.cpp
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@ -540,12 +540,10 @@ class rewrite_fn {
return none_expr();
cs_seq.linearize(cs);
unifier_config cfg;
cfg.m_discard = true;
unify_result_seq rseq = unify(m_env, cs.size(), cs.data(), m_ngen.mk_child(), m_subst, cfg);
if (auto p = rseq.pull()) {
substitution new_subst = p->first.first;
constraints new_postponed = p->first.second;
if (new_postponed)
return none_expr(); // all constraints must be solved
new_e = new_subst.instantiate_all(new_e);
if (has_expr_metavar_strict(new_e))
return none_expr(); // new expressions was not completely instantiated
@ -738,13 +736,11 @@ class rewrite_fn {
return unify_result();
cs_seq.linearize(cs);
unifier_config cfg;
cfg.m_conservative = false;
cfg.m_conservative = false;
cfg.m_discard = true;
unify_result_seq rseq = unify(m_env, cs.size(), cs.data(), m_ngen.mk_child(), m_subst, cfg);
if (auto p = rseq.pull()) {
substitution new_subst = p->first.first;
constraints new_postponed = p->first.second;
if (new_postponed)
return unify_result(); // all constraints must be solved
rule = new_subst.instantiate_all(rule);
rule_type = new_subst.instantiate_all(rule_type);
if (has_expr_metavar_strict(rule) || has_expr_metavar_strict(rule_type))

18
tests/lean/run/rewriter11.lean Normal file
View file

@ -0,0 +1,18 @@
import algebra.ring
open algebra eq.ops
variable {A : Type}
theorem zero_mul1 [s : ring A] (a : A) : 0 * a = 0 :=
have H : 0 * a + 0 = 0 * a + 0 * a,
begin
rewrite add_zero,
rewrite -(add_zero 0) at {1},
rewrite right_distrib
end,
show 0 * a = 0, from (add.left_cancel H)⁻¹
theorem zero_mul2 [s : ring A] (a : A) : 0 * a = 0 :=
have H : 0 * a + 0 = 0 * a + 0 * a,
by rewrite [add_zero, -(add_zero 0) at {1}, right_distrib],
show 0 * a = 0, from (add.left_cancel H)⁻¹