Summary

We have described a tool for grammar development in which tree descriptions are used to provide an abstract specification of the linguistic phenomena relevant to a particular language. In grammar development and maintenance, only the abstract specifications need to be edited, and any changes or corrections will automatically be proliferated throughout the grammar. In addition to lightening the more tedious aspects of grammar maintenance, this approach also allows a unique perspective on the general characteristics of a language. Defining hierarchical blocks for the grammar both necessitates and facilitates an examination of the linguistic assumptions that have been made with regard to feature specification and tree-family definition. This can be very useful for gaining an overview of the theory that is being implemented and exposing gaps that remain unmotivated and need to be investigated. The type of gaps that can be exposed could include a missing subcategorization frame that might arise from the automatic combination of blocks and which would correspond to an entire tree family, a missing tree which would represent a particular type of transformation for a subcategorization frame, or inconsistent feature equations. By focusing on syntactic properties at a higher level, our approach allows new opportunities for the investigation of how languages relate to themselves and to each other.