/sci/ - Science & Math

>>11085365
How about
https://ncatlab.org/nlab/show/classifying+topos

Also that woman which did work on brigdes and had this controvery some years ago, I think she went in that direction.
Just search for "classifying" on nLab, or maybe moduli space.
I mean I suppose all things Teichmüller also go in that direction, and the Japanese guy does a "big theory" of this. Although it may be too arithmetical for you.

I'd also like to know more about it btw.

>>11085398
I think I wrote the bulk of the catamorphism Wikipedia article years ago. On that not, look at F-algebras and the general theory of formal arithmetic of types.
https://arxiv.org/pdf/math/9405205.pdf
If you're explicit about your bijections, you can do cool stuff like "taking the square root" of data types X (that is to say, give concrete meaning to power series of stuff like X^(1/2) or 1/(X+1))
On that note again, there's a recent cool set of talk slides by Bauer on explicit bijections in combinatorics and the question what they should be (and he's shilling dependent types and hott)

http://math.andrej.com/wp-content/uploads/2019/07/What-is-an-explicit-bijection-FPSAC-2019-slides-with-presenter-notes.pdf

>>10994258
based annoying phrase poster

[math] \forall S.\, \forall (X \in S).\, \exists Y. \ X-Y = \{ \} [/math]

This is the spookiest thread I've seen in a while.

>>9717622
>taking the kindergarten definition of division literally

>>9717831
>implying functions have to be continuous

>>9717845
>>9718105
>>9718566
>implying all operations are invertible

>>9717891
>implying division is repeated subtraction