Jomi Fred Hubner, University of Blumenau, Brazil

Michael Wooldridge,University of Liverpool, UK

Preface xi

Acknowledgements xvii

1 Introduction 1

1.1 Autonomous Agents 1

1.2 Characteristics of Agents 2

1.3 Multi-Agent Systems 5

1.4 Hello World! 7

2 The BDI Agent Model 15

2.1 Agent-Oriented Programming 15

2.2 Practical Reasoning 17

2.3 A Computational Model of BDI Practical Reasoning 20

2.4 The Procedural Reasoning System 22

2.5 Agent Communication 25

3 The Jason Agent Programming Language 31

3.1 Beliefs 32

3.2 Goals 40

3.3 Plans 41

3.4 Example: A Complete Agent Program 58

3.5 Exercises 65

4 Jason Interpreter 67

4.1 The Reasoning Cycle 67

4.2 Plan Failure 86

4.3 Interpreter Configuration and Execution Modes 93

4.4 Pre-Defined Plan Annotations 97

4.5 Exercises 98

5 Environments 101

5.1 Support for Defining Simulated Environments 102

5.2 Example: Running a System of Multiple Situated Agents 109

5.3 Exercises 114

6 Communication and Interaction 117

6.1 Available Performatives 118

6.2 Informal Semantics of Receiving Messages 119

6.3 Example: Contract Net Protocol 130

6.4 Exercises 135

7 User-Defined Components 139

7.1 Defining New Internal Actions 140

7.2 Customising the Agent Class 144

7.3 Customising the Overall Architecture 151

7.4 Customising the Belief Base 155

7.5 Pre-Processing Directives 160

7.6 Exercises 162

8 Advanced Goal-Based Programming 165

8.1 BDI Programming 166

8.2 Declarative (Achievement) Goal Patterns 169

8.3 Commitment Strategy Patterns 172

8.4 Other Useful Patterns 175

8.5 Pre-Processing Directives for Plan Patterns 176

9 Case Studies 179

9.1 Case Study I: Gold Miners 180

9.2 Case Study II: Electronic Bookstore 194

10 Formal Semantics 201

10.1 Semantic Rules 207

10.2 Semantics of Message Exchangein a Multi-Agent System 212

10.3 Semantic Rules for Receiving Messages 215

10.4 Semantics of the BDI Modalities for AgentSpeak 221

11 Conclusions 225

11.1 Jason and Agent-Oriented Programming 225

11.2 Ongoing Work and Related Research 227

11.3 General Advice on Programming Style and Practice 230

Appendix: Reference Guide 235

A. 1 EBNF for the Agent Language 235

A. 2 EBNF for the Multi-Agent Systems Language 236

A. 3 Standard Internal Actions 237

A. 4 Pre-Defined Annotations 255

A. 5 Pre-Processing Directives 256

A. 6 Interpreter Configuration 258

References 261

Index 269