BLOG: Probabilistic Models with Unknown Objects

Brian Milch
Bhaskara Marthi
Stuart Russell
David Sontag
Daniel L. Ong
Andrey Kolobov

Abstract: This paper introduces and illustrates BLOG, a formal language for defining probability models over worlds with unknown objects and identity uncertainty. BLOG unifies and extends several existing approaches. Subject to certain acyclicity constraints, every BLOG model specifies a unique probability distribution over first-order model structures that can contain varying and unbounded numbers of objects. Furthermore, complete inference algorithms exist for a large fragment of the language. We also introduce a probabilistic form of Skolemization for handling evidence.

Appeared in: 19th International Joint Conference on Artificial Intelligence (IJCAI): 1352-1359, 2005.

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