The role of inference is added to the capabilities of decentralized supervisors in a modal logic setting for discrete-event systems. In previous work, a decentralized supervisor made a control decision through formal reasoning, using only information obtained from direct observation of a given system. The framework is extended so that when a supervisor cannot make a definitive control decision based on its own knowledge of the system, the supervisor may reason about whether other supervisors have sufficient knowledge to eventually make the correct control decision.