proposition: Lemma inordi1 n i : i < n -> (@inord n i.+1 = i.+1 :> nat).
proof: Proof. move=> Hi; by rewrite inordK. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(fingroup perm morphism presentation) mathcomp(ssralg poly ssrint) permcomp tools permuted combclass congr