Question

Write the logic expression (Z = …) for the diagram shown below.
X
Y
U1
NOT
U2
NOT
U3
OR2
Z

Answer 1

To write the logic expression based on your description of the circuit, let's break down the components:

1. **Inputs:**
- X
- Y

2. **NOT gates:**
- U1 operates on X, producing NOT X (¬X).
- U2 operates on Y, producing NOT Y (¬Y).

3. **OR gate (OR2):**
- U3 is an OR gate that combines the outputs from U1 and U2, so the output from the OR gate is (¬X OR ¬Y).

Finally, the output Z can be expressed as:

\[ Z = ¬X + ¬Y \]

Where "+" denotes the logical OR operation.

Thus, the complete logic expression for Z in terms of X and Y is:

\[ Z = ¬X + ¬Y \]