∀ {α : Type u_1} [inst_1 : DecidableEq α] {g : Equiv.Perm α} {a : α} (w : α)
  (h : List.idxOfNth w [g (g a)] {g a, g (g a)}.card + 1 ≤ (List.filter (fun x => decide (x = w)) []).length),
  (List.findIdxs (fun x => decide (x = w)) [])[List.idxOfNth w [g (g a)] {g a, g (g a)}.card] < [].length