Question

Which of the following is always true ?

• A. $(p\Rightarrow q)\equiv \sim q\Rightarrow \sim p$
• B. $\sim (p\wedge q)\equiv \vee p\vee \sim q$
• C. $\sim (p\Rightarrow q)\equiv p\wedge \sim q$
• D. $\sim (p\vee q)\equiv \sim p\wedge \sim q$

Answer 1

Answer: (A)

$p\Rightarrow q\equiv \sim p\vee \therefore \sim (p\Rightarrow q)\equiv p\wedge q$