∀ {α : Type u_1} [inst_1 : DecidableEq α] {g : Equiv.Perm α} {a : α} (w w_1 : α)
  (h :
    List.idxOfNth w [g (g a)] (List.idxOfNth w [g (g a)] 1) + 1 ≤ (List.filter (fun x => decide (x = w_1)) []).length),
  (List.findIdxs (fun x => decide (x = w_1)) [])[List.idxOfNth w [g (g a)] (List.idxOfNth w [g (g a)] 1)] < [].length