Chapter 7, Problem 5PE

Explanation of Solution

Three Armstrong’s axiom:

The below are three Armstrong’s axiom and they are

• Reflexivity
  • A is considered to be set of attributes
  • $\text{B}\subseteq \text{C and B}\subseteq \text{A then A}\to \text{B}$
• Augmentation
  • A is considered to be set of attributes
  • $\text{B}\to \text{C, then AB}\to \text{AC}$ will also hold
• Transitivity
  • $\text{ A}\to \text{B and B}\to \text{A}$, then $\text{A}\to \text{C}$ can also be hold.

Soundness of the Pseudo-transitivity rule:

Pseudo-transitivity rule states that,

When $\text{α}\to \text{β}$  and $\text{γβ}\to \text{δ}$ holds, $\text{αγ}\to \text{δ}$ then can also hold