these are the binary operations ie each is

Question

These are the binary operations; i.e., each is applied to two relations or sets. These two relations can be union compatible excluding in case of Cartesian product. Two relations R (A₁, A₂,....., A_n) and S (B₁, B₂,......,B_n) are said to be union compatible if they have the similar degree n and domains of the corresponding attributes are also the similar

i.e. Domain (Ai) = Domain (Bi) for 1<=i<=n.