category-theory

In the following diagram, it is not possible to drag Y on to the end of the arrow, despite it being empty.

In such a situation, it makes sense to allow Y to be dragged on top of the empty node.

The Graphs module has built-in support for Graphviz drawing of graphs. It should also support visualizing graph homomorphisms.

A starting point is in #555, which visualizes the codomain graph using colors.

The website here needs to show the most recent release.

https://zio.github.io/zio-prelude/docs/overview/overview_index#installation

Complete algorithm: http://web.cecs.pdx.edu/~mpj/pubs/polyrec.html

We can already draw arbitrary permutations as sequences of swaps, but this can clutter diagrams unnecessarily.
An easy fix is to define Permutation boxes, with an appropriate refactoring of the drawing module.

These could then be constructed by calling diagram.permute as proposed in issue oxford-quantum-group/discopy#17.

One design decision that needs to be tak

• untabify
• indent
• align where needed