Do the following two declarations involving automatic return type work the same? If so, why?

I'm confused why the book I'm reading says that the following two declarations have the same effect:

template<typename T1, typename T2> auto max (T1 a, T2 b) -> decltype(b<a?a:b);

template<typename T1, typename T2> auto max (T1 a, T2 b) -> decltype(true?a:b);

In the first declaration, the return type of max(a, b) could be the type of a, or the type of b. In the second declaration, the return type is the type of a. How can the two declarations have the same effect?

Here is the passage that I read: