The design of this system demonstrates how flexible and natural user interactions can be carried out using a system with a naturally flexible control structure. A processing-based taxonomy for ellipsis resolution that we developed is used to analyze our coverage of intersentential ellipsis. The semantic chart parser is further extended to allow several closely related sentences to be treated in a single chart. This allows the relationship between the sentences to be used in a simple way to select between competing alternative interpretations, and provides a natural means of resolving complex elliptical utterances. 
