SNePS is simultaneously a logic-based, frame-based, and network-based KRRA system. It uses an assertional model of knowledge, in that a SNePS knowledge base (KB) consists of a set of assertions (propositions) about various entities. Its intended model is of an intensional domain of mental entities—the entities conceived of by some agent, and the propositions believed by it. The intensionality is primarily accomplished by the absence of a built-in equality operator, since any two syntactically different terms might have slightly different Fregean senses.