proposition: Lemma dom_ordfreshT h x t : fresh h <= t -> x \in dom h -> x != t.
proof: Proof. by move=>H1 /dom_ordfresh H2; case: ltngtP (leq_trans H2 H1). Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval) pcm(options prelude pred finmap rtc seqext useqord uslice uconsec)