Question: 1. Prove Darwen's "General Unification Theorem." Which of the rules of the previous two exercises did you use? Which mks can be derived as special cases of the theorem?
2. Define (a) the closure of a set of FDs; (b) the closure of a set of attributes under a set of FDs.
3. List the set of all FDs satisfied (for all time) by the shipments relation SP.
4. Here is a set of FDs for a relation R(A.B.CD.B.F.G ).
A → B
BC → DE
AEF → G
Compute the closure (4,C); under this set. Is the FD ACF → DG implied by this set?