Commit 05bf88b7 authored by Ralf Jung's avatar Ralf Jung

prove list_find_proper

parent 97ab0949
......@@ -916,6 +916,14 @@ Section find.
change (list_fmap B A f y) with (f <$> y). (* FIXME it simplified too much *)
rewrite IH. by destruct (list_find (P ∘ f) y).
Lemma list_find_proper (Q : A → Prop) `{∀ x, Decision (Q x)} l :
(∀ x, P x ↔ Q x) →
list_find P l = list_find Q l.
intros HPQ. induction l as [|x y IH]; [done|]. simpl.
erewrite decide_iff by done. by rewrite IH.
End find.
(** ** Properties of the [reverse] function *)
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