Motivation analysis, abductive unification, and nonmonotonic equality

摘要

Motivation analysis in story comprehension requires matching an action mentioned in the story against actions which might be predicted by possible explanatory motivations. This requires matching constants from the story against Skolem functions in the possible motivations (assuming a normal first-order representation of stories, plans, etc.). We will show that extending unification to allow for unifying two things if they are nonmonotonically equal does exactly what is needed in such cases. We also show that such a procedure allows for a clean method of noun-phrase reference determination. The work described here has all been implemented.