proposition: Lemma oevPtUn_sub a k ks v z0 f : valid (pts k v \+ f) -> {subset ks <= dom f} -> oeval a ks (pts k v \+ f) z0 = oeval a ks f z0.
proof: Proof. move=>W F; apply: oevPtUn=>//; apply/negP=>/F. by rewrite (negbTE (validPtUnD W)). Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)