∀ {α : Type u_1} [inst_1 : DecidableEq α] {g : Equiv.Perm α} {a : α} (w_1 : α),
  List.idxOfNth w_1 [g a, g (g a)] 0 + 1 ≤ (List.filter (fun x => decide (x = w_1)) [g a, g (g a)]).length →
    List.idxOfNth w_1 [g a, g (g a)] 0 < (List.findIdxs (fun x => decide (x = w_1)) [g a, g (g a)]).length