“…In order to approximate fractional derivatives, a number of methods have been proposed (e.g., [27,29,30]). Unlike integer order derivatives, which are local operators, the singular nature of the kernel in the definition (1) or (2) of non-integer order derivatives makes the problem global; indeed, the value of On the other hand, the presence of a significantly increasing persistent memory, with respect to the integer order case, adds to the complexity of the numerical treatment of related differential problems, especially for long-time integration.…”