proposition: Lemma validPtUnE v2 v1 k f : valid (pts k v1 \+ f) = valid (pts k v2 \+ 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)