1. Solve the following relational expressions for above relations. a. PName(RAge 25(User)) b. Rid>20Age!=31(User) c. Ruser.Occupationld=DOccupation.Occupationld(User X Occupation)

Does the symbol in the line second from the last the empty set?

b. Identify the systems from task (2a) that demonstrate closure, i.e., the result of the operation always produces an element in the set.c. Identify the systems from task (2a) that have an identity element.

3. Let A = {1,2, 3} and B = {1,2, 3,4}. The relations R1 = {(1,1), (2,2), (3,3)} and R2 = {(1,1), (1,2), (1,3), (1,4)} can be combined using set operations. Find the following: a. R1 U R2 b. Rị n R2 c. R1 \ R2 d. R2 \ R1