Binary relations, endorelations and transitive closures

Relations are an important vehicle to write specifications. In this article
we study some properties of binary relations. First we start from binary
relations in general with domain, range, composition, images etc.

In the second part we study endorelations i.e. binary relations where the type
of the domain and the range are the same. The most important endorelations are
transitive relations. Transitive relations have a close connection to closure