Remember the truth tables for basic logical operations (and, or, not, implication). A contradiction is always false, and a tautology is always true
For \( S_1 : (p \rightarrow q) \land (p \land \sim q) \), the truth table is:
\( p \) | \( q \) | \( p \rightarrow q \) | \( p \land \sim q \) | \( S_1 \) |
---|---|---|---|---|
T | T | T | F | F |
T | F | F | T | F |
F | T | T | F | F |
F | F | T | F | F |
From the truth table, \( S_1 \) is a Contradiction, as \( S_1 \) is always false.
For \( S_2 : (\sim p \land q) \lor (p \land \sim q) \), the truth table is:
\( p \) | \( q \) | \( p \land q \) | \( \sim p \land q \) | \( p \land \sim q \) | \( (\sim p \land q) \lor (p \land \sim q) \) | \( S_2 \) |
---|---|---|---|---|---|---|
T | T | T | F | F | F | F |
T | F | F | F | T | T | T |
F | T | F | T | F | T | T |
F | F | F | F | F | F | F |
From the truth table, \( S_2 \) is a Tautology, as \( S_2 \) is always true.
Hence:
\( S_1 \) is Contradiction, and \( S_2 \) is Tautology.