 In combination with a functional equation that allows to liberate from a G-function "G"("z") any factor "z""ρ" that is a constant power of its argument "z", the closure implies that whenever a function is expressible as a G-function of a constant multiple of some constant power of the function argument, "f"("x") = "G"("cx""γ"), the derivative and the antiderivative of this function are expressible so too.The wide coverage of special functions also lends power to uses of Meijer's G-function other than the representation and manipulation of derivatives and antiderivatives.For example, the definite integral over the positive real axis of any function "g"("x") that can be written as a product "G"1("cx""γ")·"G"2("dx""δ") of two G-functions with rational "γ"/"δ" equals just another G-function, and generalizations of integral transforms like the Hankel transform and the Laplace transform and their inverses result when suitable G-function pairs are employed as transform kernels.