proposition: Lemma domPtUnE k v f : k \in dom (pts k v \+ f) = valid (pts k v \+ f).
proof: Proof. by rewrite domPtUn inE eq_refl andbT. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)