FLOC 2018: FEDERATED LOGIC CONFERENCE 2018
Term rewriting characterisation of LOGSPACE for finite and infinite data

Author: Łukasz Czajka

Paper Information

Title:Term rewriting characterisation of LOGSPACE for finite and infinite data
Authors:Łukasz Czajka
Proceedings:FSCD Presented Papers
Editor: Helene Kirchner
Keywords:LOGSPACE, implicit complexity, term rewriting, infinitary rewriting, coinduction
Abstract:

ABSTRACT. We show that LOGSPACE is characterised by finite orthogonal tail-recursive cons-free constructor term rewriting systems. This result is non-trivial, because in contrast to previous work on characterising LOGSPACE by tail-recursive cons-free programs we do not impose any fixed evaluation strategy. We provide a LOGSPACE algorithm which computes constructor normal forms. We then use this algorithm in the proof of our main result: that simple stream term rewriting systems characterise LOGSPACE-computable stream functions as defined by Ramyaa and Leivant. This result concerns characterising logarithmic-space computation on infinite streams by means of infinitary rewriting.

Pages:20
Talk:Jul 10 16:10 (Session 57A: Complexity)
Paper: