A specialization of extensional representation predicate (q.v.) whose instances relate situations to individuals that are involved in them in various ways. As such, each role has its first argument-place constrained to (see Arg Isa) instances of some specialization of situation, and its other argument-places constrained to instances of some specialization of individual. Note that the sort of involvement a given role attributes to an individual in a situation might be either active or passive (cf. doer and affected object), either central or peripheral (cf. primary moving object and assistant), either physical or conceptual (cf. moving object and Info Transferred). Individuals can be involved in situations in the relevant way without directly participating in the situations. For example, an agent may be involved in an event which it does not temporally intersect by being affected by it (thus affected agent is an instance of role). Important specializations of role are binary role predicate and its specialization predicate describing actors in events.