"The door refused to open. It said, "Five cents, please.”
He searched his pockets. No more coins; nothing.
"I'll pay you tomorrow," he told the door. Again, it remained locked tight.
"What I pay you," he informed it, "is in the nature of a gratuity; I don't have to pay you."
"I think otherwise," the door said. "Look in the purchase contract you signed when you bought this conapt.”