Propositional Logic 0E6B1C
1. **Problem statement:** Translate the English statements into propositional logic expressions with clear proposition definitions.
2. **Define propositions for (a):**
- $S$: The server is running.
- $D$: The database is corrupted.
- $B$: The backup system will activate.
- $L$: Data will be lost.
- $A$: The administrator intervenes immediately.
3. **Translate (a):**
- "The server is not running or the database is corrupted" translates to $\neg S \lor D$.
- "Either the backup system will activate or data will be lost" translates to $B \lor L$.
- "Unless the administrator intervenes immediately" means if $A$ then the previous condition may not hold, so the implication is modified.
4. **Full expression for (a):**
$$ (\neg S \lor D) \to ((B \lor L) \land \neg A) $$
5. **Define propositions for (b):**
- $P$: The student passes the course.
- $F$: The student scores above 85% on the final exam.
- $A$: The student has perfect attendance.
- $S$: The student scores above 70%.
- $G$: The student plagiarized.
6. **Translate (b):**
- "Passes if and only if" means $P \leftrightarrow$ (condition).
- Condition: either $F$ or ($A$ and $S$), provided they did not plagiarize ($\neg G$).
7. **Full expression for (b):**
$$ P \leftrightarrow ((F \lor (A \land S)) \land \neg G) $$
**Final answers:**
(a) $$ (\neg S \lor D) \to ((B \lor L) \land \neg A) $$
(b) $$ P \leftrightarrow ((F \lor (A \land S)) \land \neg G) $$