 Once he has pointed out what he takes to be the questionable inference, Frege takes it that the burden of argument is squarely with Hilbert: if Hilbert thinks that the consistency of \(\textit{AX}_{G}\) follows from either the consistency of \(\textit{AX}_{R}\) or from the satisfiability of \(R_{\textit{AX}}\), then it is up to Hilbert to show this. Frege does not go out of his way to demonstrate that the crucial inference is invalid, but seems to take his point to have been essentially made once he has pointed out the need for a justification here. 