For the 0/1 loss function $L_i^{(0/1)}$ defined in equation (1.7) of page 9, my understanding of "0/1 loss function" is that its non-zero value should be 1. But when $y_i\ne{\rm sign}(\overline W\cdot\overline{X_i})$, the value of $L_i^{(0/1)}$ is 2 instead of 1. So, should we change equation (1.7) to $$L_i^{(0/1)}=\frac{1}{4}(y_i-{\rm sign}(\overline W\cdot\overline{X_i}))^2=\frac{1}{2}(1-y_i\cdot{\rm sign}(\overline W\cdot\overline{X_i}))?$$