proposition: Lemma omf_fresh_lt x h : fresh h <= x -> um_filterk [ pred k | k < x ] (f h) = f h.
proof: Proof. by move=>H; apply/fresh_lt/leq_trans/H/fresh_omf. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval) pcm(options prelude pred finmap rtc seqext useqord uslice uconsec)