@jaywengrow

Under Abstract Data Types, 3rd paragraph it reads:

Our stack also contains methods that push a new element onto the end of self.data, pop an element from the beginning of self.data, and read the first element from the self.data array.

I believe this should read:

pop an element from the end of self.data, and read the last element from the self.data array.

Since stack is LIFO and page 134 defines end as being the top of the stack.