Representation of RelationsRelations can be represented in many ways. Some of which are as follows: 1. Relation as a Matrix: Let P = [a_{1},a_{2},a_{3},.......a_{m}] and Q = [b_{1},b_{2},b_{3}......b_{n}] are finite sets, containing m and n number of elements respectively. R is a relation from P to Q. The relation R can be represented by m x n matrix M = [M_{ij}], defined as M_{ij} = 0 if (a_{i},b_{j}) ∉ R 1 if (a_{i},b_{j} )∈ R Example The matrix of relation R is shown as fig: 2. Relation as a Directed Graph: There is another way of picturing a relation R when R is a relation from a finite set to itself. Example 3. Relation as an Arrow Diagram: If P and Q are finite sets and R is a relation from P to Q. Relation R can be represented as an arrow diagram as follows. Draw two ellipses for the sets P and Q. Write down the elements of P and elements of Q columnwise in three ellipses. Then draw an arrow from the first ellipse to the second ellipse if a is related to b and a ∈ P and b ∈ Q. Example The arrow diagram of relation R is shown in fig: 4. Relation as a Table: If P and Q are finite sets and R is a relation from P to Q. Relation R can be represented in tabular form. Make the table which contains rows equivalent to an element of P and columns equivalent to the element of Q. Then place a cross (X) in the boxes which represent relations of elements on set P to set Q. Example The tabular form of relation as shown in fig:
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