Peter Linz Edition 5 Exercise 12.2 Question 7 (Page No. 311)

Question

Let $G_1$ be an unrestricted grammar, and $G_2$ any regular grammar. Show that the problem

                                                                    $L(G_1) \space\cap L(G_2) = \phi $

is undecidable for any fixed $G_2,$ as long as $L(G_2)$ is not empty.