A very nice article. A fun fact: 0^0 is not undefined here. In fact, a^0 = 1 for all a. One suggestion: say "equivalence" of types, rather than "equality". (Y

A very nice article. A fun fact: 0^0 is not undefined here. In fact, a^0 = 1 for all a. One suggestion: say "equivalence" of types, rather than "equality". (You do this, once.)