Workshop TERMGRAPH 2004

Abstract

Term graph rewriting is concerned with the representation of expressions as graphs and their evaluation by rule-based graph transformation. The advantage of using graphs rather than strings or trees is that common subexpressions can be shared, which improves the efficiency of computations in space and time. Sharing is ubiquitous in implementations of programming languages: many implementations of functional, logic, object-oriented and concurrent calculi are based on term graphs. Term graphs are also used in symbolic computation systems and automated theorem proving.

Research in term graph rewriting ranges from theoretical questions to practical implementation issues. Many different research areas are included, for instance: the modelling of first- and higher-order term rewriting by (acyclic or cyclic) graph rewriting, the use of graphical frameworks such as interaction nets and sharing graphs to model strategies of evaluation (for instance, optimal reduction in the lambda calculus), rewrite calculi on cyclic higher-order term graphs for the semantics and analysis of functional programs, graph reduction implementations of programming languages, and automated reasoning and symbolic computation systems working on shared structures.