∀ {R : Type u_2} {L : Type u_1} [inst : CommRing R] [inst_1 : LieRing L] [inst_2 : LieAlgebra R L]
  [inst_3 : LieAlgebra ℚ L] (D : LieDerivation R L L),
  IsNilpotent ↑D → ∀ (x : L), (fun x => (IsNilpotent.exp (-↑D)) x) ((IsNilpotent.exp ↑D).toFun x) = x