proposition: Lemma fresh_omf h : fresh (f h) <= fresh h.
proof: Proof. by case: f=>s [m H] /=; rewrite H fresh_omap. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval) pcm(options prelude pred finmap rtc seqext useqord uslice uconsec)