%E Teodor Rus %X Klaim is an experimental programming language that supports a programming paradigm where both processes and data can be moved across different computing environments. The language relies on the use of explicit localities, and on allocation environments that associate logical localities to physical sites. This paper presents a temporal logic for specifying properties of Klaim programs. The logic is inspired by Hennessy-Milner Logic (HML) and the ?-calculus, but has novel features that permit dealing with state properties to describe the effect of actions over the different sites. The logic is equipped with a consistent and complete proof system that enables one to prove properties of mobile systems. %D 2000 %L eprints332 %K Mobile Code Languages - Temporal Logics of Programs - Coordination Models %S Lecture Notes in Computer Science %A Rocco De Nicola %A Michele Loreti %R 10.1007/3-540-45499-3_25 %B Algebraic Methodology and Software Technology (AMAST 2000) %T A Modal Logic for KLAIM %P 339-354 %V 1816 %I Springer %O Original publication available at www.springerlink.com