proposition: Lemma FAx_0S n: GA 0 n.+1 = 0.
proof: Proof. case w: (GAr n.+1 0 n.+1 == 0); first by rewrite /GA (eqP w). by move: (GAr_notz (negbT w)) => /esym/eqP;rewrite Zeckp_eq0. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path fintype div bigop binomial) mathcomp(prime finset ssralg ssrnum ssrint)