Should the variables (x and y and z) in transitive relation be different numbers? or x,y, and z can be equal?

For example we have:

R = { {1,1}, {1,2} , {1,3} }

Is R transitive? because we have:

{1,1} {1,1} => {1,1}

{1,1} {1,2} => {1,2}

{1,1} {1,3} => {1,3}

Thanks