-a1, a2, and a3 are int pointers, right? However, we can 'consider' them to be arrays. Am I okay with this here?
-a1 and ptr2ptr are NOT of the same type, because ptr2ptr is a pointer to a pointer (it uses double indirection), and a1 is a pointer (using single indirection). ptr2ptr is a bit more 'wild' of a type than a1. ***AM I OKAY WITH THIS HERE***???