proposition: Lemma S2_small : ((S_[2] 0 = 0 ) * (S_[2] 1 = 2) * (S_[2] 2 = 4) * (S_[2] 3 = 8) * ( S_[2] 4 = 14) * (S_[2] 5 = 20) * (S_[2] 6 = 28))%type.
proof: Proof. by rewrite /dsum_alphaL /conv /= /dsum_alpha -!(big_mkord xpredT) unlock /=; compute. Qed.
imports: mathcomp(all_ssreflect finmap) hanoi(extra)