proposition: Lemma cast_bseq_id n (eq_nn : n = n) bs : cast_bseq eq_nn bs = bs.
proof: Proof. by rewrite (eq_axiomK eq_nn). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype path)