proposition: Lemma validPtUnI v1 k f : valid (pts k v1 \+ f) -> [&& C k, valid f & k \notin dom f].
proof: Proof. by rewrite validPtUn. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)