The expression $$ \sim $$ ($$ \sim $$ p $$ \to $$ q) is logically equivalent to :

The Boolean expression ((p $$ \wedge $$ q) $$ \vee $$ (p $$ \vee $$ $$ \sim $$ q)) $$ \wedge $$ ($$ \sim $$ p $$ \wedge $$ $$ \sim $$ q) is equivalent to :

Contrapositive of the statement " If two numbers are not equal, then their squares are not equal." is :

If q is false and p $$ \wedge $$ q $$ \leftrightarrow $$ r is true, then which one of the following statements is a tautology ?