Syntax and semantics of a high-level intermediate representation for ASF+SDF

Developing a compiler for asdf has been a challenging task. The compilation of asdf is performed using an intermediate language muasf, an abstract syntax representation of asdf. Although asdf is quite simple to use, it provides a number of features which have an unclear semantics. By means of a number of examples in muasf and a more mathematical notation a number of these semantic issues are clarified. These examples are helpful for both the compiler designer and the specification writer.