proposition: Lemma omfUn f h1 h2: valid (h1 \+ h2) -> f (h1 \+ h2) = f h1 \+ f h2.
proof: Proof. by case: f=>s [m X] V /=; rewrite !X omapUn. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)