Recall from Chapter 2.1 that a linear threshold function (abbreviated LTF) is a boolean-valued function $f : \{-1,1\}^n \to \{-1,1\}$ that can be represented as \begin{equation} \label{eqn:generic-LTF} f(x) = \mathrm{sgn}(a_0 + a_1 x_1 + \cdots + a_n x_n) \end{equation} for some constants $a_0, a_1, \dots, a_n \in {\mathbb R}$.

[...]

## Recent comments

Ohad Klein: In 26, in the "Affine subspace partition" definition, "may b...Ohad Klein: In the very end of prop 12, I think there should be an index...Ohad Klein: In 25 (also in the book) "one one child".Noam Lifshitz: In corollary 17, should it be $\widehat{\mathrm{Maj}_n}(S) =...Ohad Klein: In 49 (56 in the book), it looks like a typo: $E[f_i(y^(j))]...Ryan O'Donnell: Hope so; I'm quite happy with it so far. (Thanks to all who...Yi Zhang: I got it now!!