proposition: Lemma umcnt0 p : um_count p Unit = 0.
proof: Proof. by rewrite /um_count umfilt0 dom0. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)