proposition: Lemma pair_le_anti a b: good_pair a -> good_pair b -> ((a <= b) && (b <= a)) = (a == b).
proof: Proof. rewrite /pair_le /= (mulnC b.2) (mulnC b.1) - eqn_leq => ga gb. case: eqP; first by move/(good_pair_prop ga gb) => ->; rewrite eqxx. by case: eqP => // ->; rewrite mulnC. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype order bigop ssralg) mathcomp(div ssrnum ssrint rat prime path binomial) mathcomp(tuple finset) gaia(fibm)