proposition: Lemma umcnt_le0 A p (h : natmap A) t : valid h -> {in dom h, forall k, t < k} -> um_count (predI p (le t)) h = 0.
proof: Proof. by rewrite -umcnt_umfilt=>V /(umfilt_le0 V) ->; rewrite umcnt0. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval) pcm(options prelude pred finmap rtc seqext useqord uslice uconsec)