proposition: Lemma slt_splitR x y ks1 ks2 : y != x -> y \notin ks1 -> x <[ks1++x::ks2] y.
proof: Proof. by move=>N Y; rewrite slt_cat slt_cons eq_refl andbT (negbTE Y) N orbT. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval order) pcm(options prelude ordtype seqext)