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2026-06-18 12:22:24 UTC

Cheng Zhang on Nostr: Category theoretical proofs always follows the pattern: nothing happens, nothing ...

Category theoretical proofs always follows the pattern: nothing happens, nothing happens, nothing happens, then an interesting problem is solved.
This really is the elegance of category theory: it is able to express a hard solution problem in seemingly trivial steps.

However, I feel this really illustrate some of the failure of communication for category theory:
- Many attempts simply stop before the "solved a problem" step. The learner often just see a slightly different encoding of an existing problem, and feels "don't know what to do with it", even when the encoding seems general.
- Many attempts seek to solve a problem that the learner is not interested in. If people don't get experience with the hard problem first, then it is hard to feel the categorical proofs.
- Finally, I don't feel "category theory without proof" is a good approach. In my naive view, I still feel category theory is a powerful vessel for elegant proofs, but does not offer much insight in encoding: categorical encoding often feels no different from their elementary counterpart. This property is valuable in proofs, as we can go from a very light encoding into deep theorems really fast, but it is an unnecessary cognitive burden for people who don't need to do proofs.