A motion closed world asumption

Yaman Fusun, Dana Nau, V. S. Subrahmanian

Research output: Contribution to journalConference articlepeer-review

4 Scopus citations


Yaman et. al. [Yaman et al., 2004] introduce "go theories" to reason about moving objects. In this paper, we show that this logic often does not allow us to infer that an object is not present at a given place or region, even though common sense would dictate that this is a reasonable inference to make. We define a class of models of go-theories called coherent models. We use this concept to define a motion closed world assumption (MCWA) and develop a notion of MCWA-entailment. We show that checking if a go-theory has a coherent model is NP-complete. An in atom checks if a given object is present in a given region sometime in a given time interval. We provide sound and complete algorithms to check if a ground in literal (positive or negative in atom) can be inferred from a gotheory using the MCWA. In our experiments our algorithms answer such queries in less than 1 second when there are up to 1,000 go-atoms per object.

Original languageEnglish (US)
Pages (from-to)621-626
Number of pages6
JournalIJCAI International Joint Conference on Artificial Intelligence
StatePublished - 2005
Externally publishedYes
Event19th International Joint Conference on Artificial Intelligence, IJCAI 2005 - Edinburgh, United Kingdom
Duration: Jul 30 2005Aug 5 2005

ASJC Scopus subject areas

  • Artificial Intelligence


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