CIS 125

8– DeMorgan’s Law

 

Note: The tilde (~) is used to denote a logical inversion, or NOT, operation.

The symbol v is used to represent the OR operator, while the ^ symbol represents the AND operator.

 

For problems 1-4, use truth tables to determine if each pair of propositions are equivalent

 

1.         Ø (p ^ q)

            Øp v Øq

            e.g. is Ø (p ^ q) equivalent to Øp v Øq for every combination of truth values of p and q?

 

 

 

 

 

 

 

 

 

2.         Ø (p ^ q)

            Øp v q

 

 

 

 

 

 

 

 

 

3.         Ø (p v q)

            Øp ^ Øq

 

 

 

 

 

 

 

 

 

4.         Øp ^ q

            Ø (p v Øq)

 

 

 

 

 

 

 

 

 

For problems 5-8 attempt to simplify the expression by applying DeMorgan’s law.

 

5.         Ø (Øp v q)

 

 

 

 

6.         Ø (Øp v Øq)

 

 

 

 

7.         Øp ^ (Øq v Ør)

 

 

 

 

8.         Ø (Øp v q) ^ Ør