proposition: Lemma valid_dom_map x : valid (dom_map x) = valid x.
proof: Proof. by rewrite /dom_map valid_omap. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)