Answer: Logic Lights #131

The lamp is OFF. It stays dark!

Gate by gate

1. A OR B → ON OR ON = ON
2. C OR D → ON OR OFF = ON
3. (A OR B) OR (C OR D) → ON OR ON = ON
4. NOT ((A OR B) OR (C OR D)) → NOT ON = OFF

The same circuit in Python

Python has the same three gates built in: and, or and not. ON is True and OFF is False.

A = True
B = True
C = True
D = False

lamp = not ((A or B) or (C or D))
print("Is the lamp on?", lamp)

When you run it, it prints:

Is the lamp on? False