3. Given the following set of functional dependencies, use Armstrong's axioms to derive (i), (ii), and

(iii).

1. X→ Y

2. Z→Y

3. V → XYZ

4. XZ → V

(1)

(ii) XZ → YV

(iii) XZ → VXYZ

V → VXYZ

Write each derivation (proof), justifying each step, the same way we do it in the presentation (e.g.

see slide 9). Don't forget to write which axiom is used for each step.