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Comment by kccqzy

I took a look at the table of contents and found that the second chapter is about the well-ordering principle. That’s surprising to me because I’ve only heard of the well-ordering theorem by Zermelo, which is a fundamental theorem in set theory, stating that any set has a well-ordering assuming the axiom of choice. It’s amazing and mind-bending in its own right (imagine a well-ordering for reals), but is clearly not very relevant to computer science.

I find the well-ordering principle slightly bewildering. It seems to presuppose the existence of an ordering on natural numbers and then prove this principle. But I’ve never been taught things this way; you always construct the natural numbers from Peano and define the ordering first, then you can actually prove the well-ordering principle rather than leaving it as an axiom.

parent kccqzy 10 months ago

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