“…to E. The generalized Lévy-Laplacian ∆ l L of order l ≥ 0 is the second-order linear differential operator associated with S l which is defined by S l (F ) = C l ((F e n , e n )), F ∈ L(E, E * ). 7,10 This definition coincides for l = 0 with that of the LaplaceVolterra operator and for l = 1 with that of the classical Lévy-Laplacian. We also consider nonclassical Lévy-Laplacians ∆ L R associated with linear operator R : span{e n : n ∈ N} → E which we define as second-order linear differential operators D SR , where S R (F ) = C 1 ((FRe n , Re n )), F ∈ L(E, E * ).…”