proposition: Lemma eval_oevUmfilt a p f z0 : eval a p f z0 = oeval a (dom (um_filter p f)) (um_filter p f) z0.
proof: Proof. apply: eq_in_oevF =>k v H; rewrite In_umfilt. split; last by case. split=>//; move: H; move/dom_umfilt => [v' [H H1]]. by rewrite (In_fun H1 H0) in H. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)