2.20. Asserting Beliefs

The agent will be John (the believer), the act is the mental act of believing, and the object of John's act of believing will be a proposition. So, to tell Cassie that John believes that Opus can fly,

evaluate:

(describe (assert agent John
                  act believe
                  object (build object Opus ability fly)))

Note that we built but did not assert that Opus can fly. We did, however, assert that John believes this. So, Cassie believes that John believes that Opus can fly, and John believes that Opus can fly. (Sometimes we say that the proposition that Opus can fly is now in John's ``belief space'' but not (directly) in Cassie's belief space, whereas the proposition that John believes that Opus can fly is in Cassie's belief space.)