Question

Explain De Morgan's theorem with example.

Answer 1

De-Morgan has suggested two theorems which are extremely useful in Boolean Algebra. The two theorems are discussed below.

Theorem 1

• The left hand side (LHS) of this theorem represents a NAND gate with inputs A and B, whereas the right hand side (RHS) of the theorem represents an OR gate with inverted inputs.
• This OR gate is called as Bubbled OR.

Table showing verification of the De Morgan's first theorem −

Theorem 2

• The LHS of this theorem represents a NOR gate with inputs A and B, whereas the RHS represents an AND gate with inverted inputs.
• This AND gate is called as Bubbled AND.

Table showing verification of the De Morgan's second theorem −