Welcome to the Clowder Project!
The Clowder Project is an online reference work and wiki for category theory and mathematics. It is built using Gerby, created by Pieter Belmans and Raymond Cheng, which is a fork of plasTeX. The Clowder Project follows the massively collaborative model started by the Stacks Project or the Automorphic Project.
The project is also available as a PDF, which you can download using the following link: Download the book as a PDF.
As a completely static website hosted on GitHub pages, there is currently no system for on-site comments like those in the Stacks Project, Kerodon, or the Automorphic Project.
However, there's a dedicated Discord server, which you can join here. There you'll find channels for discussion and comments, hopefully partly making up for the lack of an in-site comment system. There's also an updates channel, recording major news and additions currently being worked on.
In general, any and all comments, no matter how small (even things like very small typos), are extremely welcome, as are contributions.
Some further notes on the Clowder Project (from Emily de Oliveira Santos, the current main author and editor):
Placeholder Symbols and Future Style. Currently, a number of macros have been defined using placeholder symbols, and look very ugly as a result.
This is because I eventually plan to replace them with (the math font for) Darwin, a free and open-source typeface project I'm currently working on, which will eventually allow me more freedom in writing these notes:
You can find more details about Darwin at its GitHub repository or website.
Footnotes. There are lots of footnotes, due to how the original PDFs were created. They automatically expand when you hover your mouse over them; here's an example[1].
Large Diagrams and the Zoom In Feature. This work features many diagrams that are unfortunately too large to be comfortably legible in their native size. To compensate for this, it is possible to click on them to expand their size by 200%, or alternatively open them as separate images in new tabs by right-clicking and then selecting “Open image in new tab”.
A Note on Style. There are a few uncommon stylistic choices made throughout these notes:
- Every proposition, theorem, lemma, etc. needs to come with a proof, even if the latter simply reads “Omitted.”. This is to ensure results without proof are clearly labeled as such.
- There's a considerably larger amount of repetition than is usual in a math text, as well as non-linearity. This is done with the intention of making the Clowder Project work also as a wiki, making individual sections and subsections more self-contained.
Preferences. You can change the font of the site, the style of the PDFs, as well as turn on dark mode by clicking the gear button at the top of the page.
PDF Styles. The PDFs for each chapter as well as for the whole book are generated using four different styles, as summarised in the following table:
Style | Class | Font | Theorem Environments |
---|---|---|---|
Style 1 | book |
Alegreya Sans | tcbthm |
Style 2 | book |
Alegreya Sans | amsthm |
Style 3 | book |
Arno* | amsthm |
Style 4 | book |
Computer Modern | amsthm |
*To be replaced with Linus Romer's Elemaints when it is released.
Support. If you like this work and would like to support it financially, you can do so at Ko-Fi:
I've been struggling financially for the past couple months and my current source of income is unfortunately very unstable and fragile, so any donations would go a long way in ensuring I'm able to continue working on this project.
The current monthly supporters are listed in the Contributors page.