Weird thing on Spivak's definition of ordered pairs

 In the appendix of the third chapter of Spivak's Calculus, on case 1 of his definition of ordered pairs he admits that (1, 1) = {1} (from the way sets are defined).

I don't get it. That is not a pair. What am I missing?


Popular posts from this blog

An interview with Steve Wozniak by Jessica Livingston cured my AI anxiety

What if regular exercise is the best cognitive exercise?