The logically equivalent preposition of $p \Leftrightarrow q$ is
$\left( {p \Rightarrow q} \right) \wedge \left( {q \Rightarrow p} \right)$
$p \wedge q$
$\left( {p \wedge q} \right) \vee \left( {q \Rightarrow p} \right)$
$\left( {p \wedge q} \right) \Rightarrow \left( {q \vee p} \right)$
The logical statement $(p \Rightarrow q){\wedge}(q \Rightarrow \sim p)$ is equivalent to
Statement $-1 :$ $\sim (p \leftrightarrow \sim q)$ is equivalent to $p\leftrightarrow q $
Statement $-2 :$ $\sim (p \leftrightarrow \sim q)$ s a tautology
Negation of “Paris in France and London is in England” is
Among the statements
$(S1)$: $(p \Rightarrow q) \vee((\sim p) \wedge q)$ is a tautology
$(S2)$: $(q \Rightarrow p) \Rightarrow((\sim p) \wedge q)$ is a contradiction
Which of the following is a tautology?