Dataflow matrix machines (by Anhinga anhinga)

I used to understand this material in 2012-2014 (I even mentioned it in our own paper published in those years), and it turned out recently that I no longer could reproduce the detailed definitions from memory.

So I am rereading this paper by Isar Stubbe, it's really nice, not excessively difficult (I usually have difficult time reading categorical papers, but this one is a pleasant exception).

Links are in the comments.