A Dynamic Model of Aspectual Composition

This paper describes results of a dynamic model of aspectual composition that demonstrates how features necessary for planning and controlling actions can also motivate and ground simple analyses of a number of aspectual phenomena. A novel feature of the model is an active computational representation for verb semantics called x-schemas, an extension of the Petri net formalism that can encode goals, resources and other features a ecting aspect. Vexing problems of aspectual composition lend themselves to simple analyses in terms of the context-sensitive interaction between verb-speci c x-schemas and a controller x-schema that captures important regularities in the evolution of events. The resulting x-schemas can be elaborated and constrained by such factors as tense, temporal modi ers, nominals and pragmatic context, providing a rich representation that supports simulative inference in language understanding.