proposition: Lemma ptsE k v : pts k v = to (UM.pts C k v) :> U.
proof: Proof. by case: U k v=>x [*]. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)