Ascending to categories of richer structures
1. A category of richer structures: Endomaps of sets
A simple example of a ‘type of structure’ T, that is used to construct a category richer than , is the idea of a single endomap, T =. A structure of that type in is just a given set with a given endomap, and the resulting category of sets-with-an-endomap is denoted accordingly by . If you remember that an endomap of a set has a special type ...