Comonad

[go] http://blog.higher-order.com/blog/2016/04/02/a-comonad-of-graph-decompositions/
- A graph can be "of the form c & g, where c is the context of one node of the graph and g is the rest of the graph with that node removed".
- c has inEdges, vertex (id), label, outEdges.
- g is the rest of the graph (a set of contexts?).
[s5bug] told me about them: https://twitter.com/s5bug/status/1343989424229498881 [a view of the agora at a node is a comonad]