For each of the following, state whether or not it is True or False and justify
ID: 3630739 • Letter: F
Question
For each of the following, state whether or not it is True or False and justify your answer; assuming that R, S and T are 3 relations with the same set of attributes. The intersection operation is commutative, i.e., R^S = S R. The difference is associative, i.e., R- (S- T) = (R- S)- T. The union distributes over the intersection, i.e., R (S T) = (R S) (R T).Explanation / Answer
a)true as set of elements common to R & S remains the same b)false as in R-(S-T) those elements of R are removed which are not in S-T while in (R-S)-T those elements of R are removed which are not in S and then those elements are removed from remaining which are not in T => we remove those elements of R which are either not in S or in T c)true as in both case elements of R are included with the common elements of S and T
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