proposition: Lemma ptsD_lt V t1 t2 : t1 < t2 -> predD (lt t2) (le t1) =1 [pts k (v : V) | t1 < k < t2].
proof: Proof. by move=>T [k v] /=; rewrite -ltnNge. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval) pcm(options prelude pred finmap rtc seqext useqord uslice uconsec)