Class (mathematics)
In collection theory and its mathematical applications, classes are collections of collections (or other mathematical objects) that can be disagreeed by the nature of the shares shared by all members. Some classes are collections (for example, classes made up of all even numbers), but some are not (such as classes of all ordinals or classes of all collections). A class that is not a collection is called a true class. One is the collection of classes that are called "subclasses". In mathematics, there are many objects that are too large for the set, but must be described by class, like large categories and super real numbers. To prove that a given "thing" is a true class, the general practice is to prove that this "thing" has at least an ordinal number of elements. For an example of this proof, see Full Freedom. ...