package satex

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String diagram generator for LaTeX


Dune Dependency






Satex takes descriptions of string diagrams in the form of categorical compositions and converts them to string diagrams drawn in TikZ.

Published: 07 Nov 2023


Satex is a string diagram generator for LaTeX. It takes as input a formula such as

(1 * delta) * (mu * 1)

(appropriately written in the LaTeX file) and produces a diagram such as

generated using TikZ.

It is inspired from Catex (see also the documentation) for which the sources were unfortunately not available.

In case you have a problem, please file a bug report at the following url:

General usage

In order to use satex in your LaTeX file, you should first include the style file:


You should then declare the operators you want to use in the format

\deftwocell[options]{name : m -> n}

which declares an operator named name with m inputs and n outputs. The options in options allow changing the way the operator is displayed and so on. For instance,

\deftwocell[triangle]{mu : 2 -> 1}

will declare the following operator:

One can then generate diagrams by using commands of the form


where expr is a categorical expression involving operators and identities. The identity on n wires is simply written as the corresponding number and compositions are noted *: toplevel compositions are vertical ones and those inside parenthesis are horizontal. For instance

\twocell{(2 * mu) * (1 * mu) * mu}

will typeset

A run of pdflatex on your file, say file.tex, will generate a file named file.satex. You should then run

satex file.satex

which will generate a file file.satix containing the generated TikZ figures, which are automatically included in the next run of pdflatex on your file.

Options for operators


Various shapes are available for operators:

  • circle (default one):

  • triangle:

  • rectangle:

  • mergeleft / mergeright: /

  • cup / cap: /

  • crossing / crossingr: /

  • braid / braidl: /

  • crossing' / braid': /

  • blank:

The dimension of the shape can be adjusted with the labelwidth and labelheight parameters.

Labels on operators

Labels are indicated between double quotes. For instance

\deftwocell[triangle,"\mu"]{mu : 2 -> 1}


Their vertical position can be adjusted with the position parameter (between 0 and 1).

Colors on operators

Colors can be specified with fill=color option, e.g.

Labels on wires

The special operator label allows adding labels to wires. The option d or u indicates whether the labels should be put down or up, and the above syntax is used for labels. For instance

\twocell{label[d,"x","y"] * mu * label[u,"z"]}


Inline operators

You can use operators which have not been declared beforehand: the syntax is (m -> n)[options] to use an operator with m inputs, n outputs and given options. For instance,

(1 * (1 -> 2)[rectangle,"f"]) * ((2 -> 1)["g"] * 1)



Horizontal space can be adjusted by using operators of the form space2.8 which adds an horizontal space of 2.8 (formally this is an operator with no inputs and outputs).

Vertical space can be adjusted by changing the height parameter of one of the operators on the line.

Dependencies (3)

  1. menhir >= "20180703"
  2. ocaml >= "4.07.0"
  3. dune >= "2.0"

Dev Dependencies


Used by