Let A be the non-empty set of children in a family. The relation ‘x is a brother of y’ on A is
Let r denotes the relation ‘x is brother of x’. Let xA. If x is a girl, then we cannot say x is brother of x.
(x, x)R
R is not reflective
Let (x, y) R
x is a brother of y.
y may or may not be a boy.
We cannot say that (y, x) .
R is not symmetric
Let (x, y) R and (y, z) R
x is brother of y and y is brother of z.
x is brother of z (x, z) R
R is transitive