@TechReport{ it:1999-004, author = {Amnon H. Eden and Yoram Hirshfeld and Amiram Yehudai}, title = {Towards a Mathematical Foundation for Design Patterns}, institution = {Department of Information Technology, Uppsala University, and Tel Aviv University}, department = {Division of Computer Systems}, year = {1999}, number = {1999-004}, month = may, abstract = {We identify a compact and sufficient set of building blocks which constitute most design patterns of the GoF catalog: uniform sets of classes or functions, function clans, class hierarchies, and regularities (morphisms) thereof. The abstractions observed are manifested within a model in symbolic logic and defined in LePUS, a declarative, higher order language. LePUS formulae concisely prescribe design patterns in a general, complete, and accurate manner. We provide a natural, condensed graphic notation for every LePUS formula and demonstrate how design patterns are faithfully portrayed by diagrams in this notation. We conclude by defining refinement (specialization) between patterns by means of predicate calculus and illustrate how the logical formalism of LePUS facilitates tool support for the recognition and implementation of design patterns.} }