Automata, Languages and Programming

LOCALITY IN HODULAR SYSTEHS R. J. R. Back and H. Hannila Department of Computer Science University of Helsinki Modularity of programs is studied from a semantic point of view. A simple model of modular systems and modularization mechanisms is presented, together with correctness criteria for modular systems. A concept of locality of modular systems is defined; it is a property which "good" modular decompositions should have. The locality of certain kinds of modularization mechanisms is studied, and the results are applied to parameterless procedures.