### Now you know

"From this proposition it will follow, when arithmetical notation has been defined, that 1+1=2."

In the pages leading up to it, they introduce the cardinal numbers 1, 2, and 0 (in that order) and finally they prove that "0 and 1 are the only numbers less than 2."

(I found this on Good Math, Bad Math, which is surprisingly interesting when it's not talking about category theory. But then, I'm still blaming category theory for everything that was wrong with 18.904.)

## 2 Comments:

I'll read the article sometime when I'm not tired and Arthur is sitting next to me to answer questions, but my immediate reaction was to think of Oliver. ;-)

Actually, Arthur sent me instead to the wikipedia entry on Principia, and then to the group with the fake name Nicolas Bourbaki

http://en.wikipedia.org/wiki/Nicolas_bourbaki and then he slid along a tangent to the Axiom of Choice. More than I can cope with right now.

Post a Comment

<< Home