Chapter 3 minor question

[missflash]

I have a minor question at Chapter 3.

Why probability of belonging to cluster 1 was calculated as the following [Figure 1] rather than this?

v = (1 - p_trace) * norm_pdf(x, loc=center_trace[:, 1], scale=std_trace[:, 1]) >
p_trace * norm_pdf(x, loc=center_trace[:, 0], scale=std_trace[:, 0])

[Figure 1]

Thank you for your wonderful book!