Question

Among the statements :
(S1) $(( p \vee q ) \Rightarrow r ) \Leftrightarrow( p \Rightarrow r )$
(S2) $(( p \vee q ) \Rightarrow r ) \Leftrightarrow(( p \Rightarrow r ) \vee( q \Rightarrow r ))$

• A. only (S2) is a tautology
• B. both (S1) and (S2) are tautologies
• C. only (S1) is a tautology
• D. neither (S1) nor (S2) is a tautology

Answer 1

Answer: (D)

$S_2 \equiv(p \vee q) \Rightarrow r \Leftrightarrow((p \Rightarrow r) \vee(q \Rightarrow r))$