Lacan's Response to Hit the Leap

Xinghua: I have yet to find anybody who's thought is more systematic and whose thought hangs together more tightly than Lacan's work. The real is that which is excised from the symbolic's founding moments, he says. But where does he go with it after that? Xinghua: It really starts to pop here in his response to hit the leap. Who is writing a response to Freud's 1925 essay on negation?