e) S= {B |B is a binary string of length 4 with no two [] [] [] [] [] [] consecutive Os and no two consecutive 1s} f) S= {R|R is a symmetric relation on {0, 1}} [] [] [] [] [] [] g) S= {R|R is an equivalence relation on {0, 1}} [] [] [] [] [] [] h) S= {F|F is a Boolean function of degree 2} [] [] [] [] [] [] i) S= {G|G is a non-isomorphic graph with 6 vertices [] [] [] [] [] [] whose degrees are 2,2,2,3,4,4}