proposition: Lemma expx_pnat x n b: x ^ (cons zero n b) = exp_F x n.+1.
proof: Proof. by rewrite /T1exp /T1split eqxx expO_n0 T1mul1n. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(fintype bigop)