p.25 error

[thinkplaydo82]

There's an extra edge on the graph at the top which shouldn't be there I think

Apologies in advance for any breaches of etiquette; I'm new to the ways of github!

[spamegg1]

Right, the edge between $v_1$ and $v_3$ at the "base", should not be there.
This is the book's mistake since I copied the image from there! 😆