CALL FOR PAPERS Mathematical Structures in Computer Science, Special Issue on Rewriting Calculi and Higher-Order Reductions Following from the success of the workshops on rewriting calculus, there will be a special issue of the journal Mathematical Structures in Computer Science (MSCS, Cambridge University Press) on Rewriting Calculi and Higher-Order Reductions. Submissions for this special issue are hereby solicited. The integration of first-order and higher-order paradigms has been one of the main problems raised since the beginning of the study of programming language semantics and of proof environments. This has been handled either by enriching first-order rewriting with higher-order capabilities or by adding to lambda-calculus algebraic features. The rewriting calculus has been introduced as a general means to uniformly integrate rewriting and lambda calculus. This calculus makes explicit and first-class all of its components: matching (possibly modulo given theories), abstraction, application and substitutions. The rewriting calculus is designed and used for logical and semantical purposes. It could be used with powerful type systems and for expressing the semantics of rule based as well as object oriented paradigms. It allows one to naturally express exceptions and imperative features as well as expressing elaborated rewriting strategies. This special issue of the MSCS will be devoted to the foundations of the rewriting calculus and of related systems combining matching and higher-order features. Topics for the special issue include, but are not limited to, the following aspects of these calculi: - operational semantics, - type systems, - models, - associated logics, - implementation issues, - applications. Submissions should be sent electronically to rho-editors@loria.fr by 15th January 2006 (all submissions will be acknowledged). Information about the journal, including style files, can be found at: http://www.cambridge.org/uk/journals/journal_ifc.asp?mnemonic=MSC Submissions will be refereed according to the usual very high standards of MSCS. Horatiu Cirstea and Maribel Fernandez will serve as guest editors for this special issue. Final decisions on editorial matters rest with the editor-in-chief of MSCS.