An example of the IP rule in use is:

P ^ Q (P ^ Q)

Proof: 1. P Premise

2. Q Premise

3. P ^ Q P for IP

4. P 3 Simplification

5. False 1, 4 Contradiction

QED 1-5 IP

Give a formal proof for the following tautology by using the IP rule.

b. (A + B) (CVA C v B) C. (A + B)^(B C) (A v B C)