 Welcome to the session. Let us discuss the following problem. Today, let A is equal to 1, 2, 3, the number of relations containing 1, 2 and 1, 3 which are reflexive and symmetric, but not transitive is A1, B2, C3, D4. Now let us write the solution. The smallest reflexive relation set A containing 1, 2 and 1, 3, D4, C3, D4.