For an arbitrary set A, let’s define some important types of relations on A.
Reflexive relation
A relation R on A is a reflexive relation if (a,a)∈R for every element that is a∈A. If there is an element b∈A so that (b,b)∈R, then R is not a reflexive relation. Let’s take the set M={α,β,γ} and consider the following relations: