Basic Electrical and Electronics Engineering: Unit IV: Digital Electronics

Duality Theorem

Properties | Boolean Algebra

The table shows the list theorems of Boolean algebra and four of it postulates.

BASIC THEOREMS AND PROPERTIES

Duality

1. A + Ā = 1, since 

2. A . Ā = 0, since 

The table shows the list theorems of Boolean algebra and four of it postulates

(i) A+0 = A

(ii) A.1 = A

(iii) A+ Ā = 1

(iv) A . Ā = 0

 (v) A+A = A

(vi) A . A = A

(vii) A + 1 = A

(viii) A . 0 = 0

Ā = A

Theorem

=A+ AB

=A (1+B)

= A.1

= A

Theorem

A+ ĀB = A+B

A+ ĀB

(A + Ā) (A + B)

[Using distributive law] [A + A = 1]

1. (A + B)

A+ ĀB = (A + B)

Theorem

A.( Ā + B) = AB

A (Ā + B) by using distributive law (A . Ā) = 0

 (A . Ā) + (A.B)

A . (Ā + B) = AB

Basic Electrical and Electronics Engineering: Unit IV: Digital Electronics : Tag: : Properties | Boolean Algebra - Duality Theorem