4) For each of the following relation schemas and sets of FDs:

a) R(A, B, C, D) with FDs AB C, C D, and D A.

b) R(A, B, C, D, E) with FDs AB C, C D, D B, and D E.

Decompose the relations, as necessary, into collections of relations that are in BCNF. Do not forget to consider FDs that are not in the given set, but follow from them.

5)

For each of the relation schemas and sets of FDs of Question 4. Decompose the relations, as necessary, into collections of relations that are in 3NF.