James uses socially appropriate behavior to greet peers but does so up to ten times in one class period. His teacher decides to use a type of differential reinforcement to lower the rate of his behavior but she does not want to eliminate it completely. She decides to deliver reinforcement (ex: computer time) to James if he greets peers five or fewer times during the class period. If he greets peers more than five times, he does not receive reinforcement. Which kind of reinforcement is being used?