Summary: Size­Change Termination for Term Rewriting #
Ren’e Thiemann and J˜urgen Giesl
LuFG Informatik II, RWTH Aachen, Ahornstr. 55, 52074 Aachen, Germany
{thiemann|giesl}@informatik.rwth­aachen.de
Abstract. In [13], a new size­change principle was proposed to verify
termination of functional programs automatically. We extend this princi­
ple in order to prove termination and innermost termination of arbitrary
term rewrite systems (TRSs). Moreover, we compare this approach with
existing techniques for termination analysis of TRSs (such as recursive
path orderings or dependency pairs). It turns out that the size­change
principle on its own fails for many examples that can be handled by stan­
dard techniques for rewriting, but there are also TRSs where it succeeds
whereas existing rewriting techniques fail. In order to benefit from their
respective advantages, we show how to combine the size­change princi­
ple with classical orderings and with dependency pairs. In this way, we
obtain a new approach for automated termination proofs of TRSs which
is more powerful than previous approaches.
1 Introduction
The size­change principle [13] is a new technique for automated termination
analysis of functional programs, which raised great interest in the functional

Source: Ábrahám, Erika - Fachgruppe Informatik, Rheinisch Westfälische Technische Hochschule Aachen (RWTH)

Collections: Computer Technologies and Information Sciences