Which of the following statement is a tautology?
$\left[ {\left\{ {p \wedge \left( {\left( {q \vee t} \right) \wedge p} \right)} \right\} \to \left\{ {\left( {q \vee r} \right) \wedge \left( {p \vee t} \right)} \right\}} \right] \leftrightarrow \left[ { \sim \left( {q \vee r} \right) \to \sim p} \right]$
$\left\{ {p \wedge \left( {\left( {q \vee t} \right) \wedge p} \right)} \right\} \leftrightarrow \left[ {\left( {q \vee r} \right) \to p} \right]$
$\left\{ {p \wedge \left( {\left( {q \vee t} \right) \wedge p} \right)} \right\} \leftrightarrow \left[ {q \wedge r \wedge p} \right]$
$\left\{ {p \wedge \left( {\left( {q \vee t} \right) \wedge p} \right)} \right\} \leftrightarrow t$ (where $t$ denotes tautology)
The statement among the following that is a tautology is
The propositions $(p \Rightarrow \;\sim p) \wedge (\sim p \Rightarrow p)$ is a
For integers $m$ and $n$, both greater than $1$ , consider the following three statements
$P$ : $m$ divides $n$
$Q$ : $m$ divides $n^2$
$R$ : $m$ is prime,
then true statement is
If $p$ and $q$ are simple propositions, then $p \Leftrightarrow \sim \,q$ is true when
Which of the following statements is a tautology?