. This paper surveys the work of many researchers on rewriting logic since it was first introduced in 1990. The main emphasis is on the use of rewriting logic as a semantic framework for concurrency. The goal in this regard is to express as faithfully as possible a very wide range of concurrency models, each on its own terms, avoiding any encodings or translations. Bringing very different models under a common semantic framework makes easier to understand what different models have in common and how they differ, to find deep connections between them, and to reason across their different formalisms. It becomes also much easier to achieve in a rigorous way the integration and interoperation of different models and languages whose combination offers attractive advantages. The logic and model theory of rewriting logic are also summarized, a number of current research directions are surveyed, and some concluding remarks about future directions are made. Table of Contents 1 In...

this paper I briefly sketch recent work on meta-logical foundations that seems promising as a conceptual basis on which to achieve the goal of formal interoperability. Specificaly, I will briefly discuss:

This paper presents a logic language (called Distributed Logic Objects, DLO for short) that supports objects, messages and inheritance. The operational semantics of the language is given in terms of rewriting rules acting upon the (possibly distributed) state of the system. In this sense, the logic underlying the language is Rewriting Logic. In the paper we discuss the implementation of this language on distributed memory MIMD architectures, and we describe the advantages achieved in terms of flexibility, scalability and load balancing. In more detail, the implementation is obtained by translating logic objects into a concurrent logic language based on multi-head clauses, taking advantage from its distributed implementation on a massively parallel architecture. In the underlying implementation, objects are clusters of processes, objects' state is represented by logical variables, message-passing communication between objects is performed via multi-head clauses, and inheritance is mappe...

Data Type Specification, in combination with modal logics for formalizing the process of building systems from interconnected components. This combination of logical and categorical techniques has also been applied to parallel program design languages in the style of UNITY [14] and IP [41], providing semantics for modularization techniques based on the notion of superposition. This has resulted in the development of a programming design language called Community [33]. Two formalisms that provide explicit support for object systems and can reason about their rewriting logic specifications have been recently developed. One is a version of the modal -calculus proposed by Lechner [48, 49] for reasoning about object-oriented Maude specifications. Another is Denker's objectoriented distributed temporal logic DTL + [24, 22], that extends the DTL and D 1 distributed object temporal logics of Ehrich and Denker [30, 23, 29]. Lechner [48, 49] uses her version of the modal -calculus to identif...