proposition: Lemma sorted_dom f : sorted (@ord K) (dom f).
proof: Proof. by rewrite !umEX; case: (UMC.from f)=>[|[]]. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)