proposition: Lemma findUnPt k v f : valid (f \+ pts k v) -> find k (f \+ pts k v) = Some v.
proof: Proof. by rewrite joinC; apply: findPtUn. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)