No violation of the Leibniz rule. No fractional derivative

We demonstrate that a violation of the Leibniz rule is a characteristic property of derivatives of non-integer orders. We prove that all fractional derivatives D-alpha, which satisfy the Leibniz rule D(alpha()fg) = (D(alpha)f) g + f(D(alpha)g), should have the integer order alpha = 1, i.e. fractional derivatives of non-integer orders cannot satisfy the Leibniz rule. (C) 2013 Elsevier B. V. All rights reserved.