Boolean Simplification
1. **Problem statement:** Simplify the Boolean expression $\overline{A}B + \overline{A}\overline{B}\overline{C} + A\overline{B}\overline{C} + ABC$ and construct its circuit diagram and truth table.
2. **Expression:** $F = \overline{A}B + \overline{A}\overline{B}\overline{C} + A\overline{B}\overline{C} + ABC$
3. **Group and simplify terms:**
- Combine $\overline{A}\overline{B}\overline{C}$ and $A\overline{B}\overline{C}$ using the distributive law:
$$\overline{A}\overline{B}\overline{C} + A\overline{B}\overline{C} = \overline{B}\overline{C}(\overline{A} + A) = \overline{B}\overline{C}$$
- So expression becomes:
$$F = \overline{A}B + \overline{B}\overline{C} + ABC$$
4. **Further simplify if possible:**
- Consider the term $ABC$; no obvious overlap with $\overline{A}B$ or $\overline{B}\overline{C}$.
- This is the simplified form.
5. **Circuit diagram components:**
- Inputs: A, B, C
- Gates for terms:
- $\overline{A}B$: NOT A, AND with B
- $\overline{B}\overline{C}$: NOT B, NOT C, AND both
- $ABC$: AND A, B, C
- OR gate combines these three outputs.
6. **Truth table:** List all $2^3=8$ combinations for A, B, C and compute $F$.
| A | B | C | $\overline{A}$ | $\overline{B}$ | $\overline{C}$ | $\overline{A}B$ | $\overline{B}\overline{C}$ | $ABC$ | $F$ |
|---|---|---|--------------|--------------|--------------|------------|----------------|-------|-------|
| 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 0 | 1 |
| 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | 1 |
| 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 |
| 1 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 1 |
| 1 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| 1 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |
| 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
7. **Final answer:**
$$F = \overline{A}B + \overline{B}\overline{C} + ABC$$
Circuit contains NOT gates for $A$, $B$, and $C$, AND gates for each product term, and an OR gate to combine outputs.