Exercise 1 Design a function that given a list of lists appends them all together.

Exercise 2 Design a function that given a list of list of numbers determines if they are pairwise disjoint or not (lists are pairwise disjoint if none of them share any elements).

Exercise 3 Design a function that takes a list of books (books have a title, author, and page count) and sorts them alphabetically by title.

Exercise 4 Design a function that given a natural number n outputs the identity matrix of size n. An identity matrix can be represented as a list of list of numbers where all elements of the inner lists are 0 except the ith element in the ith list, which is 1. Here is more information on the identity matrix.

Exercise 5 Design a function that given a list of numbers and a number n replaces all occurrences of 0 with two copies of n.