... Phi- losophica Fennica, Vol.16, 1963. Moore R.C. Reasoning about knowledge and ac- 17 tion. IJCAI-5, 1977. Moore R.C. Reasoning about knowledge and ac- 18 tion. Artificial Intelligence Center, ... language is complicated and unintuitive, since, rather than reasoning directly about facts that some- one knows, we reason about the possible worlds compatible with what he knows. This transla- tion ... someone knows something then he knows that he knows it. This a- xiom is often required to reason about plans composed of several steps. It will be referred to as the positive introspec- tive...