For Exercise 4.4

I am not able to understand that in this exercise 4.4, what is actually w and do we have to consider the regularizatio also and if the formulae:

Ein(w) =1/N (Zwlin − y)T * (Zwlin − y)

how can w-wlin come in picture.

by this formula I am able to get the second term but not the second term?

Can anyone help me derive this expression or can anyone share his/her solution with me.

http://book.caltech.edu/bookforum/showthread.php?t=4512
same is the Ein used here??? is it out of sample error... I am not able to understand the conflict. What my understanding is that we have derived wlin but for a variable vector we first check how much does it vary from the wlin and multiplied by Z vector gives us how much function vary from average hypothesis and the second term gives us the error of Wlin predicting outputs. Is my understanding right??