# COMP304

## Knowledge Representation and Reasoning

### Aims

To introduce Knowledge Representation as a research area.

To give a complete and critical understanding of the notion of representation languages and logics.

To study description logic and their use;

To study epistemic logic and its use

To study methods for reasoning under uncertainty

### Syllabus

1

- Introduction to knowledge representation (KR), formalisms for KR and in particular propositional logic (1week).
- Introduction to modal and description logics (5 weeks):Modal logics: Syntax, semantics (Kripke models), model checking, theorem proving. Description logics: Syntax, semantics, satisfiability checking, expressive description logics
- Applications of modal logic: epistemic logic (3 weeks): One agent case: S5 models, specific properties; Multi-agent case: Modelling epistemic puzzles, reasoning about other''s knowledge and ignorance, alternating bit protocols; Group notions of knowledge: Distributed knowledge, common knowledge,examples; Computational models: Interpreted systems
- Handling uncertain information through probability and decision theory 2 weeks): Sample spaces; independence; conditional probability; prior and posterior probabilities; random variables; decision theory for agent systems; Bayesian networks.

### Recommended Texts

Epistemic Logic for AI and Computer Science, J.-J.Ch. Meyer and W. van der Hoek, Cambridge Tracts in Theoretical Computer Science 41, 1995.

S. Russell and P. Norvig: *Artificial Intelligence: A Modern Approach*. Prentice Hall (2003).

### Learning Outcomes

be able to explain and discuss the need for formal approaches to knowledge representation in artificial intelligence, and in particular the value of logic as such an approach;

be able to demonstrate knowledge of the basics of propositional logic

be able to determine the truth/satisfiability of modal formula;

be able to perform modal logic model checking on simple examples

be able to perform inference tasks in description logic

be able to model problems concenring agents'' knowledge using epistemic logic;

have sufficient knowledge to build "interpreted systems" from a specification, and to verify the "knowledge" properties of such systems;

be familiar with the axioms of a logic for knowledge of multiple agents;

be able to model simple problems involving uncertainty, using probability and decision theory;

be able to demonstrate knowledge of the basics of probability and decision theory, and their use in addressing problems in knowledge representation;

### Learning Strategy

Formal teaching for the whole group

small supervised exercising groups.

Formal Lectures: Students will be expected to attend three hours of formal lectures in a typical week plus one hour supervised tutorial.

Private study: In a typical week students will be expected to devote six hours of unsupervised time to private study. The time allowed per week for private study will typically include three hours of time for reflection and consideration of lecture material and background reading, and three hours for completion of practical exercises.