Truth Table Contingency
1. **State the problem:** Construct the truth table for the compound statement $ (p \to q) \lor (\neg p \land \neg q) $ and determine if it is a tautology, contradiction, or contingency.
2. **Recall definitions:**
- $p \to q$ (implication) is false only when $p$ is true and $q$ is false; otherwise true.
- $\neg p$ is the negation of $p$.
- $\land$ is logical AND.
- $\lor$ is logical OR.
3. **List all possible truth values for $p$ and $q$:**
| $p$ | $q$ |
|-----|-----|
| T | T |
| T | F |
| F | T |
| F | F |
4. **Calculate $p \to q$ for each row:**
- Row 1: $T \to T = T$
- Row 2: $T \to F = F$
- Row 3: $F \to T = T$
- Row 4: $F \to F = T$
5. **Calculate $\neg p$ and $\neg q$ for each row:**
- Row 1: $\neg T = F$, $\neg T = F$
- Row 2: $\neg T = F$, $\neg F = T$
- Row 3: $\neg F = T$, $\neg T = F$
- Row 4: $\neg F = T$, $\neg F = T$
6. **Calculate $\neg p \land \neg q$ for each row:**
- Row 1: $F \land F = F$
- Row 2: $F \land T = F$
- Row 3: $T \land F = F$
- Row 4: $T \land T = T$
7. **Calculate the entire expression $(p \to q) \lor (\neg p \land \neg q)$ for each row:**
- Row 1: $T \lor F = T$
- Row 2: $F \lor F = F$
- Row 3: $T \lor F = T$
- Row 4: $T \lor T = T$
8. **Analyze the results:** The expression is true in rows 1, 3, and 4, but false in row 2.
9. **Conclusion:** Since the expression is not always true or always false, it is a **contingency**.
**Final answer:** The statement $ (p \to q) \lor (\neg p \land \neg q) $ is a contingency.