A term-rewriting characterization of PSPACE

TL;DR

This paper introduces a new term rewriting system that characterizes the class FPS of polynomial-space computable functions, providing a simple and uniform approach to space complexity.

Contribution

It proposes an alternative TRS for FPS, showing that FPS is the minimal class containing initial functions and closed under certain operations.

Findings

New TRS characterizes FPS

FPS is minimal class with initial functions and closure properties

Simplifies understanding of space complexity

Abstract

Isabel Oitavem has introduced a term rewriting system (TRS) which captures the class FPS of polynomial-space computable functions. We propose an alternative TRS for FPS. As a consequence, it is obtained that FPS is the smallest class containing certain initial functions and closed under specific operations. It turns out that our characterization is relatively simple and suggests an uniform approach to the space-complexity.