Let R and S be equivalence relations on a set A. Prove that R S is also an equivalence relation on A. (Remark: Both

Let R and S be equivalence relations on a set A. Prove that R Ç S is also an equivalence relation on A.

(Remark: Both R and S are subsets of A × A. Their intersection R Ç S is also a subset of A × A. See also Tutorial 5, Q.2 for the situation for union of relations.)