proposition: Lemma validPtUn_cond k v f : valid (pts k v \+ f) -> C k.
proof: Proof. by rewrite validPtUn; case/and3P. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)