proposition: Lemma SCF_simpl0 a b l l': SCF(l++a::0::b::l') = SCF(l++a+b::l').
proof: Proof. by elim:l=> [| c [ /=-> | d l /= ->]] //; rewrite /= add0r !div1r invrK addrA. 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)