Page 96 - DCAP506_ARTIFICIAL_INTELLIGENCE

Artificial Intelligence Parminder Kaur, Lovely Professional University

Notes Unit 7: Symbolic Reasoning under Uncertainty

CONTENTS
Objectives
Introduction
7.1 How can we reason?

7.2 Uncertain Reasoning
7.3 Non-Monotonic Reasoning
7.4 Default Reasoning

7.5 Circumscription
7.5.1 Implementations: Truth Maintenance Systems
7.6 Summary
7.7 Keywords
7.8 Review Questions

7.9 Further Readings

Objectives

After studying this unit, you will be able to:
 Understand the concepts of non-monotonic reasoning

 Discuss the default reasoning
 Illustrate the concept of circumscription

Introduction

When we need any knowledge system to accomplish something it has not been clearly
informed how to do, it must reason. The system must work out what it requires to recognize
from what it already be familiar with. We have observed easy instance of reasoning or
sketching inferences already. For example, if we are familiar with: Robins are birds. All birds
have wings. Then if we inquire: Do robins have wings? Some reasoning has to go on respond to
the question.
7.1 How can we Reason?

To some extent this will be based on the knowledge representation selected. Although a good
knowledge representation system has to permit easy, normal and believable reasoning. We
have discussed below very wide techniques of how we may reason.
1. Formal reasoning: It implies to basic rules of inference along with logic knowledge
representations.
2. Procedural reasoning: Procedural reasoning uses procedures that state how to possibly solve
(sub) problems.

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