/sci/ - Science & Math

>concludes the existence of the integers via the axiom that the category of categories has equalizers
>calls the sides of a brick "homomorphisms", and uses this viewpoint to prove that multiplication is associative. (Exercise: Show that four-dimensional bricks behave in the same way)
>concludes that 2×2=4 by pulling back the ring structure on End(a)
>introduces fractions by narrating a story in which seven boys fight over three apple pies, and one convinces the others that they cannot have the same number of whole pies each by examining the unique symmetric bilinear map from a×a to a sending (1,1) to 1
Is Carl E. Linderholm the hero mathematics needs?

>>10938730
In the OP text: Linderholm constructs the natural numbers as a coequalizer in the category of categories, uses quadratic forms to prove that 3 is not divisible by 7, gives a non-circular proof that 22 is prime using the fact that Z/2ZZ/2Z is a field...