“…we have that α4 2 = α 4 3 = β 4 k = 0, 1 ≤ k ≤ m. Considering the following relation2mϕ(x 0 ) = 2ϕ([h, x 0 ]) = [ϕ(h), x 0 ] + [h, ϕ(x 0 )] = [α 1 1 h, x 0 ] + [h, α 4 1 e + β 4 0 x 0 ] = 2α 4 1 e + m(α 1 1 + β 4 0 )x 1 , Thus, ϕ(x 0 ) = α 1 1 x 0 . Then from ϕ(x k ) = ϕ([x k−1 , f ]), we obtain that ϕ(x k ) = α 1 1 x k for 1 ≤ k ≤ m.Hence, any 1 2 -derivation of L m is trivial.…”