This is really cool. The original post is great in putting it in terms of a concrete example. It would be cool (challenging but possible) to have a 3D visualiza

This is really cool. The original post is great in putting it in terms of a concrete example. It would be cool (challenging but possible) to have a 3D visualization of collapsing f(x)·g(y) like you describe in the context of that same example. It's certainly a useful mental model.