Therefore, total number of one-one maps from {1, 2, 3} to itself is
same as total number of permutations on three symbols 1, 2, 3 which is 3 = 6 Example 23 Let A = {1, 2, 3} Then show that  the number of relations containing (1, 2)
and (2, 3) which are reflexive and transitive but not symmetric is three