>>13359369What's the context? (I don't recognize what the context is, given the symbols ? and E. My first thought was truth value algebra, or form space, and fibre bundle, but they are on the wrong sides..)
Presumably X and Y are both arrows.
If you're not doing category, then presumably X and Y are functions. I.e. just two of them defined as one.
If you have a product category, then it's a pair of functions.
