RA expressions.

Consider relations r(R), s(S) and t(T) as shown below. (Relation r has 3 tuples, s has 4 tuples, t has 3 tuples.)

r(R)

A	B
3	d
4	e
3	e

s(S)

B	C	D
d	7	1
d	4	2
e	8	1
e	4	2

t(T)

B	C
a	3
b	4
c	5

Can we perform the operations as shown in each of the following expressions? If your answer is yes, show your work at each step of evaluation, and clearly indicate the final result. If your answer is no, explain why.

(a) _A G _{min(C), sum(D)} (r s)

(b) t (s _B(r))