proposition: Lemma consec_mem ks t1 t2 : consec ks t1 t2 -> t1 \in ks.
proof: Proof. by case/andP=>/slt_memE. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path interval order) pcm(options prelude ordtype seqext slice useqord uslice)