I'm trying to work trough the following proof of the book "Random Trees" by Michael Drmota.
I'm having trouble understanding the bounds of the integral $\int_{\gamma_1 \cup \gamma_2 \cup \gamma_3}$. Also it seems to me that $\gamma_1$ does not necessarily lie inside $\Delta$ since $x > x_0 (1 + \eta) $. My apologies if something is trivial, my complex analysis is a bit rusty. Can someone help me out?