proposition: Lemma DP_raiseK v: DP_lower (DP_raise v) = v.
proof: Proof. by rewrite /DP_lower /DP_raise /= belast_rcons. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype) mathcomp(ssrnat seq path div) mathcomp(fintype tuple finfun bigop finset binomial)