Which of the following statements is $NOT$ logically equivalent to $\left( {p \to \sim p} \right) \to \left( {p \to q} \right)$?
$\left( {p \to p} \right) \to \left( {p \to \sim p} \right)$
$q \to \left( {p \to q} \right)$
$\left( {q \to \sim p} \right) \to \left( {q \to p} \right)$
none of these
The negative of $q\; \vee \sim (p \wedge r)$ is
Which of the following is an open statement
If $P$ and $Q$ are two statements, then which of the following compound statement is a tautology?
Which of the following pairs are not logically equivalent ?
Negation of the Boolean statement $( p \vee q ) \Rightarrow((\sim r ) \vee p )$ is equivalent to