proposition: Lemma slt_rconsI x y k ks : x <[ks] y -> x <[rcons ks k] y.
proof: Proof. by move=>H; rewrite slt_rcons H (slt_memE H) if_same. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval order) pcm(options prelude ordtype seqext)