[topic] as our payloads, so that sent types would then be: [topic] -> S'Y([topic]). All of the operations except
for `maybe` would then have to emulate the operations of the List monad by hand (manually performing catmap etc).
But `maybe` could examine the [topic] as a whole and decide whether to return box(it) or box([]).
- This would be to go back to the Sem4/Sem5 choices of monads (without list), and to implement the handling of lists
+ This would be to go back to the Sem5/Sem6 choices of monads (without list), and to implement the handling of lists
by hand, as we did in the Sem1/Sem2 strategies.
Additionally, we haven't tried here to handle non-rigid noun-types. That's why we can have sent types be: