proposition: Lemma domeq2_dom_mapL x : dom_eq2 (dom_map x) x.
proof: Proof. by rewrite /dom_eq2 valid_dom_map dom_mapE !eq_refl. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)