proposition: Lemma ordfresh_dom0 h t : fresh h <= t -> t \notin 0::dom h.
proof: Proof. rewrite leqNgt; apply: contra; rewrite inE. by case/orP=>[/eqP -> //|]; apply: dom_ordfresh. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval) pcm(options prelude pred finmap rtc seqext useqord uslice uconsec)