63.2 Types of Numbers

For proper understanding, we are using the terms type and category in the next sections. These terms are used (quite inclusive) in the meaning of type and category theory in some sense. A category is a class of elements related to each other by fulfilling a common predicate. Then on the other hand the type of an object is something like the strongest category an object may live in disjointly.

The main difference between both terms is that in C an object must have exactly one type, whereas it still can belong to other categories. For example, having the integer 0 and the fraction 0/1, then both of these belong to the category ‘zero’, but it is quite obvious that nobody would expect them to be of type ‘zero’.