List of Authors......................................................................................................ix
Forward................................................................................................................xi
Author's Preface...................................................................................................xv
Chapter 1: Introduction..........................................................................................1
Motivation.........................................................................................................3
Responding to the Critics................................................................................11
The Symbol Grounding Problem....................................................................20
Contents of the Book......................................................................................28
Chapter 2: Knowledge Representation................................................................31
Overview.........................................................................................................33
Informal Languages........................................................................................35
Frames.............................................................................................................38Description Logic...........................................................................................41
Propositional and Predicate Logic..................................................................47
First-Order Logic............................................................................................53
Higher-Order Logics.......................................................................................55
First-Order Logic in SUO-KIF.......................................................................56
SUO-KIF Details............................................................................................58
Conversion to First-Order Logic.....................................................................61
Exercises.........................................................................................................68
Chapter 3: Ontologies (in the Broadest Sense)....................................................69
Introduction.....................................................................................................71
WordNet (and Why it's not an Ontology).......................................................71
Digression: Ontology Development Pitfalls...................................................78
Chapter 4: Suggested Upper Merged Ontology..................................................83
Overview.........................................................................................................86
Validation........................................................................................................89
Principles of Construction..............................................................................92
Digression - Open Research...........................................................................93
SUMO History................................................................................................94
SUMO Overview..........................................................................................101
SUMO's Eleven Modules.............................................................................105
Lower Level Ontologies...............................................................................109
Ontological Issues.........................................................................................111
Ontology Code Management........................................................................118
SUMO Details and Examples.......................................................................120
Semiotics Content.........................................................................................147
Exercises.......................................................................................................154
Chapter 5: SUMO and the WordNet Mappings.................................................157
Overview.......................................................................................................159
Interpreting Language...................................................................................164
Global WordNet............................................................................................166
The Interlingual Index..................................................................................166
Arabic and Filipino Wordnets.......................................................................168
Chapter 6: Knowledge Engineering Tools.........................................................171
Introduction...................................................................................................173
Language Generation....................................................................................175
Browsing and Display...................................................................................179
Analysis and Debugging...............................................................................182

Inference.......................................................................................................184
Higher-Order Logic......................................................................................192
Mapping, Merging and Translation..............................................................194
Working with Sigma and SUMO..................................................................195
Example Application.....................................................................................197
Browsing and Editing ..................................................................................201
Sigma Tutorial..............................................................................................202
Exercises.......................................................................................................214
Chapter 7: Using SUMO for Inference.............................................................215
Overview.......................................................................................................217
Inference.......................................................................................................218
Example Inference........................................................................................220
Proof Presentation ........................................................................................222
Resolution Theorem Proving Example.........................................................223
Normalization Algorithm..............................................................................230
Refutation Algorithm....................................................................................232
Chapter 8: Controlled English to Logic Translation..........................................235
Introduction...................................................................................................237
Simple Parsing and Interpretation.................................................................239
Issues in Translation......................................................................................241
CELT Components........................................................................................248
Chapter 9: An Application: Extending SUMO with Wikipedia........................249
Introduction...................................................................................................251
Related Work................................................................................................251
General Comparison of the Knowledge Sources..........................................253
Integration of Entities...................................................................................255
Integrating Factual Knowledge.....................................................................262
Semantics of Terms in Ontologies................................................................266
Conclusion....................................................................................................267
Summary and Conclusions................................................................................269
Answers to the Exercises...................................................................................271
Acknowledgments.............................................................................................275
References.........................................................................................................279
Index..................................................................................................................297