tikzsd

tikzsd is a Haskell program used to generate LaTeX code for string diagrams.

To use the program, one defines the categories, functors and natural transformations to be used, specifying data such as labels and shapes. After doing this, one can generate the LaTeX for images such as

by simply describing the desired natural transformation and telling the program how to space the strings.

The first example above was described (after defining F, G, unit and counit) using the code

f : & & F \\
n : unit & \\
f : F & G & F \\
n : & counit \\
f : F & & \\

while the second example above was described using the code

f : & & p1b & & & & & pi12b & pi23f & p2f \\
n : & p2-unit & & & \\
f : & & p1b & p2f & & & p2b & pi12b & pi23f & p2f \\
n : f-unit & & & p2pi12b-p1pi23b-iso & & \\
f : ff & fb & p1b & p2f & & & p1b & pi23b & pi23f & p2f \\
n : & fp1b-fp2b-iso & & & pi23-counit & \\
f : ff & fb & p2b & p2f & & & p1b & & & p2f \\
n : & & p2-counit & f-unit & & \\
f : ff & fb & & & ff & fb & p1b & & & p2f \\
n : & f-counit & fp1b-fp2b-iso & \\
f : ff & & & & & fb & p2b & & & p2f \\
n : & & p2-counit \\
f : ff & & & & & fb \\

(again, after suitable definitions).

Moreover, the program also verifies that your functors and natural transformations actually compose, and prints an error message if it detects something is wrong.

Usage

Please check out the user's manual available in the folder doc/user-manual for details on how to use the program.

The folder doc/examples contains examples of documents whose string diagrams were generated with tikzsd, along with all relevant source files. Currently, there is a writeup of a proof of the Benabou-Roubaud theorem, from which the above two diagrams were taken.

Installation

This is a Haskell project. One can clone the repository, then run stack install in the cloned repository to compile and install. The program is available on Hackage.