Closing the Gap Between Runtime Complexity and Polytime Computability

Closing the Gap Between Runtime Complexity and Polytime Computability
M. Avanzini and G.Moser
Proceedings of the 21st International Conference on Rewriting Techniques and Applications, volume 6 of Leibnitz International Proceedings in Informatics, pages 33–48, 2010.

Abstract

In earlier work, we have shown that for confluent term rewrite systems (TRSs for short), innermost polynomial runtime complexity induces polytime computability of the functions defined. In this paper, we generalise this result to full rewriting, for that we exploit graph rewriting. We give a new proof of the adequacy of graph rewriting for full rewriting that allows for a precise control of the resources copied. In sum we completely describe an implementation of rewriting on a Turing machine (TM for short). We show that the runtime complexity of the TRS and the runtime complexity of the TM is polynomially related.

Categories

Term Rewriting, Invariance, ICC, Graph Rewriting