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Type Theory [uts-001X]

Recently I have read some meta-level dependent type theory (Typst source). It might be time to re-read `leantt` paper, and start reading `lean4lean` paper/source.

The author `ice1000` has strong interest in QIIT (Quotient Inductive-Inductive Types) and QIIR (Quotient Inductive-Inductive Recursion), he has implemented `overlap` in Aya with termination check and confluence check.

Aya has a philosophy that the kernel could include pattern matching, but at the cost of no generation and translation of eliminators at present. In principle this is feasible, without `overlap`, it could be implemented by "theory of signatures", with `overlap`, it needs "Coherent and concurrent elimination for initial algebras" which I find fascinating, and have read [yeasin2011initial].

The author also has a great article on TT & Cat [zhang2021type]. His recommendation of [gundry2013tutorial] is also worth reading.

In the process of learning Topos, I wish to have a better understanding of Logic. Particularly, Curry–Howard–Lambek correspondance, Propositional truncation, and Paraconsistent logic are on the plate.

Although remotely related, I'll place Introduction to Formal Reasoning (COMP2065) in this section so I won't lose track of it.