In general, don't run the air conditioner. But do run it if the temperature is high. But even then, don't run it if the line voltage is low. And so on. Expressing these rules in defeasible logic is much more concise and natural than expressing them in classical logic.
Fuzzy logic is another nonclassical logic that is already popular with microcontrollers.
It solves a completely different problem. Fuzzy logic might say it's 0.7 hot, or something like that. Without meaning to disparage it, I think fuzzy logic is limited in some peculiar ways. In general, to make a fuzzy system work, you have to come up with numbers by experimenting. With defeasible logic, you can see in advance exactly what each rule is supposed to do.