blob: 43acfe4ba2bd3483a635aaa2b61e9ea80c12c20f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
Require Import Ring.
Require Import ArithRing.
Ltac ring_simplify_neq :=
match goal with
| [ H: ?X <> ?Y |- _ ] => progress ring_simplify X Y in H
end.
Lemma toto : forall x y, x*1 <> y*1 -> y*1 <> x*1 -> x<>y.
Proof.
intros.
ring_simplify_neq.
ring_simplify_neq.
(* make sure ring_simplify has simplified both hypotheses *)
match goal with
| [ H: context[_*1] |- _ ] => fail 1
| _ => idtac
end.
auto.
Qed.
|
