1. **State the problem:**
We want to analyze the logical equivalence of the statement $$[r \to (p \lor q)] \leftrightarrow \sim[r \to (r \lor q)]$$.
2. **Recall the implication rule:**
An implication $$a \to b$$ is logically equivalent to $$\sim a \lor b$$.
3. **Rewrite each implication:**
- $$r \to (p \lor q) \equiv \sim r \lor (p \lor q)$$
- $$r \to (r \lor q) \equiv \sim r \lor (r \lor q)$$
4. **Simplify the second implication:**
Since $$r \lor q$$ always includes $$r$$, $$r \lor q$$ is true whenever $$r$$ is true, so:
$$\sim r \lor (r \lor q) = \sim r \lor r \lor q = \text{True} \lor q = \text{True}$$
5. **Negate the second implication:**
$$\sim[r \to (r \lor q)] = \sim \text{True} = \text{False}$$
6. **Rewrite the original equivalence:**
$$[r \to (p \lor q)] \leftrightarrow \sim[r \to (r \lor q)]$$ becomes
$$[\sim r \lor (p \lor q)] \leftrightarrow \text{False}$$
7. **Equivalence to False means negation:**
$$[\sim r \lor (p \lor q)] \leftrightarrow \text{False}$$ is true only when $$\sim r \lor (p \lor q)$$ is false.
8. **Find when $$\sim r \lor (p \lor q)$$ is false:**
This is false only if both $$\sim r$$ is false and $$(p \lor q)$$ is false.
- $$\sim r$$ false means $$r$$ is true.
- $$(p \lor q)$$ false means $$p$$ is false and $$q$$ is false.
9. **Final condition for equivalence to hold:**
$$r = \text{True}, p = \text{False}, q = \text{False}$$.
**Answer:** The equivalence $$[r \to (p \lor q)] \leftrightarrow \sim[r \to (r \lor q)]$$ holds true only when $$r$$ is true and both $$p$$ and $$q$$ are false.
Logical Equivalence D5Aa3F
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