I am a graduate student at the Graduate
School of Mathematics, Nagoya University, in Nagoya, Japan. I am interested in a
wide range of topics in theoretical computer science and mathematics, most particularly those related to
category theory, type theory, programming language theory, etc. My research advisor is Professor
Jacques Garrigue, and my work is supported by the
COCTI (Certifiable OCaml Type Inference)
project, funded by the Tezos Foundation.
I received my B.S. in computer science, double majoring in international relations and minoring in
mathematics, and my M.S. in computer science, both from Tufts University, in Medford, Massachusetts, in
the United States.
For more details, please refer to my curriculum vitae (last updated October 17, 2020).
I am also a formal methods consultant and freelance software engineer, most experienced in engineering formal proof
and building working software systems with OCaml and Haskell, but with experience in a large variety of areas. You can
check my résumé for my experience in this area.
Primarily, I am interested in category theory, especially categorical logic and topos theory. I am interested in the connections between category theory,
type theory (such as homotopy type theory), and proof assistants
such as Coq. I also enjoy using the
"internal", or "synthetic" view to look at all kinds of mathematics.
More broadly speaking, I also have an interest in programming language theory and logic in computer science, as well as
applications of category theory and algebraic geometry to computer science, in general.
A lot of my research involve working with and coding in a proof assistant and/or dependently-typed programming language.
I am mainly working (with Jacques Garrigue) on designing an expressive core language for OCaml, with formalized
semantics and typing rules, that supports structural polymorphism and
type-level equality witnesses. This core language is expressive enough to encode most of modern OCaml (except for
the imperative part and the module language) without much hassle. We aim to develop a mechanized specification
and semantics for this core language, and prove the soundness of and principality of type inference for this mini-OCaml.
You can find our Coq development here, or read our brief report on this
project (presented at the CoqPL Workshop 2021).
Starting from what is already done in the Coq Mathematical Components library, I build the
necessary building blocks required to develop modern algebraic geometry, commutative algebra, and homological algebra. Currently,
I am focused on developing basic categorical notions, as well as some basic theorems in commutative algebra.
This project is still in a nascent stage, and current development effors are highly experimental. However, I would love to have some
collaborators, and I am very open to discussions!
This is a very early-stage project, but I did give a short talk about it in November 2020. You can find the
Over the course of many years, I created a lot of software for personal use. However, in the rare case that other people are
interested, they are also publicly available:
grading tool (currently unnamed): a set of Ruby scripts to help automate the task
of remote grading & grade management. Put grades in YAML files, and get grade summaries & grading emails sent out automatically.
ruby annotations on hover. You can find a demo here.
RubyPP: ruby annotation preprocessor for
Markdown. Converts ruby annotated Markdown to GitHub flavored markdown.
I am a functional programmer. My programming language of choice is OCaml,
but I sometimes also code in Haskell, and to a lesser extent in Idris and Erlang. In the rare occasion that
I code imperatively, I usually use Ruby or sometimes Python. My editor of choice is
the glorious Emacs, despite that it is well known that ed is
the standard and the best text editor.
My operating system of choice is Arch Linux: please
see my Linux page for my engagements in the Linux community.
I prefer to be referred to by the singular they, especially in a professional setting,
but I am fine with he.
In an English language setting, I often prefer to just be called "Ray". Professionally, I use my full legal name.
My name is written 亓璇睿 in Chinese characters (hanzi/kanji), and in Mandarin (technically, "modern standard Mandarin") it is pronounced
/tɕʰi˧˥ ɕɥɛn˧˥ ɻwei̯˥˩/ (IPA) . I find the best approximation
(modulo tones) to be the Japanese katakana: チー・シュエンルイ. If you can read Hanyu Pinyin or Bopomofo
(Zhuyin Fuhao), it is pronounced [qí xuán ruì] or [ㄒㄧˊ ㄏㄩㄢˊ ㄖㄨㄟˋ].
By the way, even many native Chinese speakers cannot pronounce the Chinese characters in my name, as my surname is an extremely rare one (by Chinese
standards). There are about 130,000 people with my surname in mainland China and a few hundred more in Taiwan; all of us hail from
Laiwu (莱芜), a small city near Ji'nan, the capital of Shandong Province.
If you are really interested about the origin of my name (and the Chinese classics), read on.
Both chracters are taken from the Book of Docuemnts (書經, or 尚書), one of the
Five Classics of the Chinese classics.
The first character, 璇 (of which 璿 is a variant), is taken
from the following passage: