Plan realization for complex command interaction in the UNIX help domain

Yucca-* is a consultation system which is designed to provide the UNIX user , through a friendly interface, with derailed expert advice on the use of t he UNIX command language. One of the principal design goals of this system is the ability to provide correct responses to technically complex queries whose solution may involve the interconnection of several commands, each wi th multiple options. The realization of such a goal requires two things. Fi rst, representation of dynamic knowledge about command behavior at a suffic ient level of detail to support solution of the query is needed. Second, a planning mechanism capable of interconnecting such knowledge into a cohesiv e solution must be provided. This paper first develops the command dynamics representation techniques employed in Yucca-*. It then examines in detail the plan generation mechanism which is used to solve complex dynamic querie s. Particular emphasis is placed upon those aspects of the problem which ar e unique to this particular domain.