Contact details

John Lloyd
Professor Emeritus
School of Computing
College of Engineering, Computing and Cybernetics
Australian National University
Canberra ACT 0200
Australia

Research interests

Draft book on empirical beliefs

Empirical beliefs are beliefs that are acquired from observations by an agent situated in an environment. Agents use empirical beliefs to track reality. This manuscript is a draft of a mathematical theory of empirical beliefs. In particular, it examines in detail the structure of empirical beliefs, and how to acquire and utilize them.

The account here of empirical beliefs is probabilistic and modal. Probability theory is used to model uncertainty about beliefs and provides a form of `degree of belief'. Modal operators provide doxastic and temporal aspects of beliefs. The main contributions are the introduction of the concept of a schema from which empirical beliefs are obtained, the ability to acquire from observations beliefs that are conditional distributions, the sophistication of the representation language for empirical beliefs, and the ability to reason about such beliefs.

Preface and contents of Empirical Beliefs.

Draft book as of 19 May 2022.

Some papers

• D. Chen, S. Yang-Zhao, J.W. Lloyd, and K.S. Ng, " Factored Conditional Filtering: Tracking States and Estimating Parameters in High-Dimensional Spaces", arXiv, 2024.
• M. Hutter, J.W. Lloyd, K.S. Ng, and W.T.B. Uther, "Probabilities on Sentences in an Expressive Logic", Journal of Applied Logic, 11(4), 386-420, 2013. DOI:10.1016/j.jal.2013.03.003
• J.W. Lloyd, "Higher-order Logic", Encyclopedia of Machine Learning, C. Sammut and G. Webb (editors), Springer, 502-506, 2010.
• J.W. Lloyd and K.S. Ng, "Declarative Programming for Agent Applications", Autonomous Agents and Multi-Agent Systems, 2010. DOI: 10.1007/s10458-010-9138-1.
• K.S. Ng and J.W. Lloyd, "Probabilistic Reasoning in a Classical Logic", Journal of Applied Logic, 7(2), 218-238, 2009. DOI:10.1016/j.jal.207.11.008.
• K.S. Ng, J.W. Lloyd, W.T.B. Uther, "Probabilistic Modelling, Inference and Learning using Logical Theories", Annals of Mathematics and Artificial Intelligence, 54, 159-205, 2008. DOI:10.1007/s10472-009-9136-7.
• J.W. Lloyd, "Knowledge Representation and Reasoning in Modal Higher-order Logic", 2007.
• J.W. Lloyd and K.S. Ng, "Probabilistic and Logical Beliefs", LADS 2007, LNAI 5118.
• J.W. Lloyd and K.S. Ng, "Reflections on Agent Beliefs", DALT 2007, LNAI 4897.
• J.W. Lloyd and K.S. Ng, "Learning Modal Theories", ILP 2006, LNAI 4455.
• K.S. Ng and J.W. Lloyd, "Predicate Selection for Structural Decision Trees", ILP 2005, LNAI 3625.
• J.W. Lloyd and T.D. Sears, "An Architecture for Rational Agents", DALT 2005, LNAI 3904.
• J.J. Cole, M.J. Gray, J.W. Lloyd, and K.S. Ng, "Personalisation for User Agents", AAMAS 05.
• J.W. Lloyd, "Modal Higher-order Logic for Agents", 2004.
• T. Gärtner, J.W. Lloyd, and P.A. Flach, "Kernels and Distances for Structured Data", Machine Learning, 57(3): 205-232, 2004.
• J.W. Lloyd, "Logic for Learning: Learning Comprehensible Theories from Structured Data", Springer, Cognitive Technologies Series, July 2003.
• J. Cole, J.W. Lloyd, and K.S. Ng, "Symbolic Learning for Adaptive Agents", 2003.
• T. Gärtner, J.W. Lloyd, and P.A. Flach, "Kernels for Structured Data", ILP 2002.
• J.W. Lloyd, "Higher-order Computational Logic", in Computational Logic: From Logic Programming into the Future, A. Kakas and F. Sadri (editors), Springer-Verlag, 2002.
• J.W. Lloyd, "Knowledge Representation, Computation, and Learning in Higher-order Logic".
• J.W. Lloyd, "Predicate Construction in Higher-order Logic", Electronic Transactions on Artificial Intelligence, Vol. 4(2000), Section B, pp. 21-51.
• A.F. Bowers, C. Giraud-Carrier and J.W. Lloyd, "A Knowledge Representation Framework for Inductive Learning".
• A.F. Bowers, C. Giraud-Carrier and J.W. Lloyd, "Classification of Individuals with Complex Structure", ICML2000.
• J.W. Lloyd, "Programming in an Integrated Functional and Logic Programming Language", Journal of Functional and Logic Programming, 1999(3), March 1999.
• J.W. Lloyd, "Debugging for a Declarative Programming Language", Machine Intelligence 15: Intelligent Agents, Oxford University Press, 341-359, 1999.