Summary: Cyclic Lambda Graph Rewriting
Zena M. Ariola Jan Willem Klop
Computer & Information Science Dept. Dept. of Software Technology, CWI
University of Oregon Dept. of Computer Science, Free University
Eugene, OR 97401 Amsterdam, The Netherlands
ariola@cs.uoregon.edu jwk@cwi.nl
Abstract
This paper is concerned with the study of cyclic –­
graphs. The starting point is to treat a –­graph as a
system of recursion equations involving –­terms, and
to manipulate such systems in an unrestricted man­
ner, using equational logic, just as is possible for first­
order term rewriting. Surprisingly, now the confluence
property breaks down in an essential way.
Confluence can be restored by introducing a re­
straining mechanism on the `copying' operation. This
leads to a family of –­graph calculi, which are inspired
by the family of –oe­calculi (–­calculi with explicit sub­
stitution). However, these concern acyclic expressions
only. In this paper we are not concerned with optimal­

Source: Ariola, Zena M. - Department of Computer and Information Science, University of Oregon

Collections: Computer Technologies and Information Sciences