proposition: Lemma domeq_refl f : dom_eq f f.
proof: Proof. by case: domeqP=>//; case. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)