proposition: Lemma S1_small : ((S_[1] 0 = 0) * (S_[1] 1 = 1) * (S_[1] 2 = 3) * (S_[1] 3 = 6) * (S_[1] 4 = 10) * (S_[1] 5 = 16) * (S_[1] 6 = 24))%type.
proof: Proof. by rewrite /dsum_alphaL /conv /= /dsum_alpha -!(big_mkord xpredT) unlock /=; compute. Qed.
imports: mathcomp(all_ssreflect finmap) hanoi(extra)