[zasdffaa]

Can you point to some examples of owl/sql transforms being flipped? I have trouble believing that an invertible transformation is hard (presumably each step is invertible, right), and certainly "never would have been able to discover" seems inconceivable to me.

Looking at the paper it is very dense and abstract, also 50 pages long.

Edit: on reflection I am doing a bit of sealioning which was not my intention but it does look that way. I'll try to read your paper but if you assure me cat theory really allowed you to do those things you claim, I'll accept you at your word.

[wisnesky]

You might try pages 8-16 of this presentation: https://www.categoricaldata.net/cql/lambdaconf.pdf . The examples are relational to relational and simplistic but they do illustrate running the same transformation both forward and backward, as well as show the "unit" of such a "monad". We implemented everything in public software, so hopefully the software is even better than my word! As for loading SQL to RDF specifically, I'd be happy to share that technique, but it isn't public yet- please ping me at [e-mail].