proposition: Lemma umcntPtUn p k v f : valid (pts k v \+ f) -> um_count p (pts k v \+ f) = (if p (k, v) then 1 else 0) + um_count p f.
proof: Proof. by move=>W; rewrite umcntUn // umcntPt (validPtUn_cond W). Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)