If RCA x B and S B xC, the join of R and S is a new set which is a subset of AxBxC. We will write this set as R./ S. It is defined as follows : R./ S = {(a, b, c): (a,b) E R and (b, c) E S) Let A = {1,2,3), B = {cat,dog), and C = {mouse, cheese, bone). Let R = {(1, cat), (2, cat), (2,dog),(3,dog)}, S = {(cat,mouse),(cat, cheese), (dog, cheese), (dog, bone)}. Explicitly write out the set R./S