The compound statement $(\sim( P \wedge Q )) \vee((\sim P ) \wedge Q ) \Rightarrow((\sim P ) \wedge(\sim Q ))$ is equivalent to

If the Boolean expression $( p \wedge q ) \circledast( p \otimes q )$ is a tautology, then $\circledast$ and $\otimes$ are respectively given by

Which of the following is a contradiction

The negative of the statement $\sim p \wedge(p \vee q)$ is

The contrapositive of $(p \vee q) \Rightarrow r$ is