Consider the universal relation r= {a, b, c, d, e, f, g, h, i, j} and the set of functional dependencies f.

f = {{a, b} _{c, d},

{d}=> {e, f, g},

{f, g}_{h},

{a}+{i},

{a, b} {e, g},

{a, i} + {i, j}}

(a) what is the closure of the set {a, d}?

(b) what is the key for r?

(c) what is the minimum cover for the set of functional dependencies f?

(d) decompose r into 2nf.

(e) decompose r into 3nf.