fact: Fixpoint iter1_aux k n p i (s : seq A) := if k is k1.+1 then if i + p < n then iter1_aux k1 n p i.+1 (if odd (i %/ p) then s else swap i (i + p) s) else s else s.
imports: mathcomp(all_ssreflect perm algebra.zmodp) mathcomp(zify) more_tuple nsort