Programming Research Group - University of Amsterdam - TR P9809 Introduction & Basic Tooling for CASL using ASF+SDF Bjarke Wedemeijer A few years ago an initiative was started to develop a general algebraic specification language CASL (Common Algebraic Specification Language). The designers based their work on existing algebraic languages. The goal of this initiative is to develop CASL together with a methodology for writing CASL specifications and to develop tools to support the development of CASL specifications. One of the characteristics of CASL are mixfix terms. This thesis describes the implementation of a mixfix parser in ASF+SDF. Given a preparse of a CASL specification which yields information about the signature (defined operations, constants, predicates, and variables), an SDF grammar is generated that describes CASL specialized to that signature. The specification of the mixfix parser serves as a prototype; issues such as efficiency are not addressed. The use of ASF+SDF to support the prototyping of CASL was instrumental in discovering ambiguities and other shortcomings of the grammar at an early stage and had an important influence on the design of the concrete syntax of the language.