CQL in a proarrow equipment

[sjoerdvisscher]

According to https://arxiv.org/abs/1602.03501 "all of the components of our model---including schemas, instances, change-of-schema functors, and queries - fit into a single double categorical structure called a proarrow equipment (a.k.a. framed bicategory)"

I have some Haskell proarrow equipment code here: https://gist.github.com/sjoerdvisscher/66d93e2136888ce7dcf3ed7d35718945

It would be interesting to see if we can make an instance for CQL!

[sjoerdvisscher]

My hunch is that the Morphism type should be the square.