. This paper is based on a talk presented at the CSLI Workshop on Planning and Practical Reasoning, Stanford University, June 1984. I thank Joseph Schatz for his advice and comments, and Monnett Hanvey and one of the IJCAI referees for discovering an error in an earlier draft. This research was supported

the resulting theories inappropriately special and hide the characteristic structures of nonmonotonic reasoning amid many unrelated structures. We present a more direct mathematical development of nonmonotonic reasoning free of extraneous logical and epistemological assumptions, and argue that the insights

We describe a general mechanism for the dynamic learning of default assumptions about unknown parameters in a complex problem. We evaluate the mechanism in the context of scheduling an academic conference, utilizing an existing scheduling system. We show that the assumptions help the system find

Default and non-monotonic inference rules are not really epistemological statements, but are instead desires or preferences of the agent about, the makeup of its own mental state (episternic or otherwise). The fundamental relation in non-monotonic logic is not so much self-knowledge as self-choire or seIf-determination, and the fundamental justification of the interpretation"*, and structures involved come from decision theory and economics rather than from logic and epistemology. 1.

not be interpreted as representing the official policies,

Abstract—We consider the task of scheduling a conference based on incomplete information about resources and constraints, and describe a mechanism for the dynamic learning of related default assumptions, which enable the scheduling system to make reasonable guesses about missing data. We outline

Disjunctive Logic Programming (DLP) is an advanced formalism for knowledge representation and reasoning, which is very expressive in a precise mathematical sense: it allows to express every property of finite structures that is decidable in the complexity class ΣP 2 (NPNP). Thus, under widely

Many practical planning problems necessitate the generation of a plan under incomplete information about the state of the world. In this paper we propose the notion of Assumption-Based Planning. Unlike conformant planning, which at-tempts to find a plan under all possible completions of the initial

Under the assumption that each pair of participants em communieatc secretly, we show that any reasonable multiparty protwol can be achieved if at least Q of the Participants am honest. The secrecy achieved is unconditional, It does not rely on any assumption about computational intractability. 1.

Models of document indexing and document retrieval have been extensively studied. The integration of these two classes of models has been the goal of several researchers but it is a very difficult problem. We argue that much of the reason for this is the lack of an adequate indexing model