fact: Fixpoint nat_of_list l := if l is a:: b then let r := (nat_of_list b).*2 in if a then r.+1 else r else 0.
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)