Lie triple derivations of nest algebras

Let N be a nest on a complex separable Hilbert space H, and τ(N) be the associated nest algebra. In this paper, we prove that every Lie triple derivation from τ(N) into itself is of the form X → XT − TX + h(X)I, where T∈τ(N) and h is a linear mapping from τ(N) into C such that h([[A, B], C]) = 0 for all A,B,C∈τ(N).