∀ {R : Type u_1} {L : Type u_2} [inst : CommRing R] [inst_1 : LieRing L] [inst_2 : LieAlgebra R L]
  [inst_3 : LieAlgebra ℚ L] (D : LieDerivation R L L) (h : IsNilpotent ↑D) (l : L), (D.exp h) l = (IsNilpotent.exp ↑D) l