proposition: Lemma consec_oo ks t1 t2 : consec ks t1 t2 -> &=ks `]t1, t2[ = [::].
proof: Proof. by case/consecP=>_; rewrite -nilp_hasPn=>/nilP. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval order) pcm(options prelude ordtype seqext slice useqord uslice)