“…The first generalization in the quaternionic setting is due to Brackx [8,9] who defined the k-monogenic functions to be the elements of Ker(D) k+1 , D being the Füter operator. Its analog for the (left) slice derivative ∂ I is recently introduced in [11] (see also [12,7,4]). Thus, the solution of the generalized Cauchy-Riemann equations ∂ I n+1 f | I = 0; I 2 = −1, leads to the space SR n of S-polyregular functions of level n (or order n + 1), i.e., such that the restriction to any slice C I is polyanalytic of level n. Some basic properties of this new class of S-polyregular functions have been established…”