The Synthesizer Generator is a system for automating the implementation of language-based editing environments. The editor designer prepares a specification that includes rules defining a language s context-free abstract syn- tax context-sensitive relationships display format and concrete input syntax. From this specification the Synthesizer Generator creates a display editor for manipulating objects according to these rules [Reps84]. This volume The Synthesizer Generator Reference Manual is intended as the defining document of the system. A companion volume The Synthesizer Gen- erator: A System for Constructing Language-Based Editors [Reps88] provides a more tutorial description of the system; it contains numerous examples that illustrate the specification and use of generated editors as well as chapters that explain important algorithms of the implementation. The Synthesizer Generator is a generalization of our earlier system the Cor- nell Program Synthesizer [Teitelbaum81] which was a programming environ- ment for a specific small dialect of PL/I. It featured a display-oriented syntax- directed editor an incremental compiler an execution supervisor supporting source-level debugging and a file system containing syntactically typed pro- gram fragments. Whereas PL/I was built into the Cornell Program Synthesizer the Synthesizer Generator accepts a formal language definition as input. Although originally conceived as a tool for creating Synthesizer-like environments for arbitrary pro- gramming languages the Synthesizer Generator is more broadly useful. Any textual language with a hierarchical phrase structure grammar is a candidate. vi Preface Interactive theorem proving for formal mathematics and logic for example has emerged as a particularlysuitable application.