With the modern definition, the majority of the established special functions can be represented in terms of the Meijer G-function. A notable property is the closure of the set of all G-functions not only under differentiation but also under indefinite integration. 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.