a) Suppose R is a partial order over set A. Prove or disprove that R2 is a partial order.b) Let S={(a, b):amod10=bmod10}. Prove or disprove that S is an equivalence relation over the integers.a) Let f: AA and g:AA be bijective functions. (a) Prove or disprove whether gf is injective (b) Prove or disprove whether gf is surjective.