fact: Fixpoint eotake (A : Type) d n (s : seq A) := if d is d1.+1 then if odd n then eotake d1 n./2 (otake s) else eotake d1 n./2 (etake s) else s.
imports: mathcomp(all_ssreflect perm algebra.zmodp) mathcomp(zify) more_tuple nsort