$(p\; \wedge \sim q) \wedge (\sim p \vee q)$ is
A contradiction
A tautology
Either $(a)$ or $(b)$
Neither $(a)$ nor $(b)$
$\sim (p \vee q) \vee (~ p \wedge q)$ is logically equivalent to
The statement $\sim(p\leftrightarrow \sim q)$ is :
Which one of the following is a tautology ?
The proposition $p \Rightarrow \;\sim (p\; \wedge \sim \,q)$ is
Which of the following is a statement