proposition: Lemma fusci_1 a b: Fusci 1 a b = a + b.
proof: Proof. by move: (fusci_odd 0 a b); rewrite fusci_0. 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)