Basic formulas and common formulas of logical algebra

Basic formulas and common formulas of logical algebra

Serial number Formula Serial number Formula

Proof and generalization of common formulas

1. Proof Example
Try to prove: A+AB=A
1) List the truth table to prove
2) Use the basic formula to prove
A+AB=A(1+B)=A·1=A

2. Extension Examples
1. Extension of A+AB = A+B
A+ABC = A+BC
AB+ABC = AB+C
A+AB = A+ B
AB+ABC = AB+C= A+B+C
2. Extension of AB = A+B
ABC =A+B+C
Similarly: A+B+C = ABC