Maude: Speciication and Programming in Rewriting Logic ?

Maude is a high-level language and a high-performance system supporting exe-cutable speciication and declarative programming in rewriting logic. Since rewriting logic contains equational logic, Maude also supports equational speciication and programming in its sublanguage of functional modules and theories. The underlying equational logic chosen for Maude is membership equational logic, that has sorts, subsorts, operator overloading, and partiality deenable by membership and equality conditions. Rewriting logic is reeective, in the sense of being able to express its own metalevel at the object level. Reeection is systematically exploited in Maude endowing the language with powerful metaprogramming capabilities, including both user-deenable module operations and declarative strategies to guide the deduction process. This paper explains and illustrates with examples the main concepts of Maude's language design, including its underlying logic, functional, system and object-oriented modules, as well as parameterized modules, theories, and views. We also explain how Maude supports reeection, metaprogramming and internal strategies. The paper outlines the principles underlying the Maude system implementation, including its semicompilation techniques. We conclude with some remarks about applications, work on a formal environment for Maude, and a mobile language extension of Maude.