A decision tree $T$ for $f : \{-1,1\}^n \to \{-1,1\}$ can be thought of as a deterministic algorithm which, given adaptive query access to the bits of an unknown string $x \in \{-1,1\}^n$, outputs $f(x)$. E.g., to describe a natural decision tree for $f = \mathrm{Maj}_3$ in words: “Query $x_1$, then $x_2$. If they [...]

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Ryan O'Donnell: Yes, thanks!Noam Lifshitz: In exercise 15 (Ex 18 in the book) is it true that $V_j=T_j$...Ryan O'Donnell: Thanks!Matt Franklin: Maybe two small typos in the proof of Corollary 11.67 (p. 36...Ryan O'Donnell: I see your point, although in some sense this distinction be...Ryan O'Donnell: Thank you!Ryan O'Donnell: Yep, thanks!