Let $F _ { 1 } ( A , B , C ) = ( A \wedge \sim B ) \vee [ \sim C \wedge ( A \vee B ) ] \vee \sim A$ and $F _ { 2 } ( A , B ) = ( A \vee B ) \vee ( B \rightarrow \sim A )$ be two logical expressions. Then :\\
(1) $F _ { 1 }$ is a tautology but $F _ { 2 }$ is not a tautology\\
(2) $F _ { 1 }$ is not a tautology but $F _ { 2 }$ is a tautology\\
(3) Both $F _ { 1 }$ and $F _ { 2 }$ are not tautologies\\
(4) $F _ { 1 }$ and $F _ { 2 }$ both are tautologies