Chitta Baral, Gregory Gelfond, Michael Gelfond, and Richard B. Scherl
The goal of our approach to textual inference is to answer queries about events and dates reported in texts; queries that demand inferencing with the relevant background knowledge. Our primary knowledge representation language is AnsProlog. The core inference engine is a combination of AnsProlog and Constraint Logic programming. AnsProlog is particularly useful for the representation of defaults, causal relations, and other types of common-sense knowledge. Constraint Logic Programming is needed to solve constraints involving the relationship between the sequence of actions and the dates on which the actions may have occurred. The combination of the two creates a useful tool for answering queries over texts and in particular queries that involve relatively deep reasoning.