arXiv subjects

Kasper Hagens

Publications and source records attributed to Kasper Hagens.

3 recordsLinked to original sources

arXiv2026

Templates in Rewriting Induction

Rewriting Induction (RI) is a formal system in term rewriting to establish program equivalence. The recently defined Bounded RI for higher-order Logically Constrained Term Rewriting Systems (LCSTRSs) yields a convenient proof system for analyzing real programming code. A practical challenge in RI is the automatic generation of induction hypotheses, called lemmas. While various lemma generation techniques exist for plain term rewriting, there are much fewer that consider the intricacies brought on by calculations or constraints. Taking advantage of recent developments in higher-order RI, we here present a new approach based on templates, which operates by recognising typical programming constructs as instances of higher-order functions. While templates have been used as a stand-alone method to justify the correctness of program transformations, we here consider their integration in Bounded RI to obtain a complementary lemma generation heuristic. This allows us to prove equivalences that were previously out of reach.

cs.LO↗

arXiv2026

Bounded Rewriting Induction for LCSTRSs

Rewriting Induction (RI) is a method to prove inductive theorems, originating from equational reasoning. By using Logically Constrained Simply-typed Term Rewriting Systems (LCSTRSs) as an intermediate language, rewriting induction becomes a tool for program verification, with inductive theorems taking the role of equivalence predicates. Soundness of RI depends on well-founded induction, and one of the core obstacles for obtaining a practically useful proof system is to find suitable well-founded orderings automatically. Using naive approaches, all induction hypotheses must be oriented within the well-founded ordering, which leads to very strong termination requirements. This, in turn, severely limits the proof capacity of RI. Here, we introduce Bounded RI: an adaption of RI for LCSTRSs where such termination requirements are minimized.

cs.LO↗

arXiv2024

Higher-Order Constrained Dependency Pairs for (Universal) Computability

Dependency pairs constitute a series of very effective techniques for the termination analysis of term rewriting systems. In this paper, we adapt the static dependency pair framework to logically constrained simply-typed term rewriting systems (LCSTRSs), a higher-order formalism with logical constraints built in. We also propose the concept of universal computability, which enables a form of open-world termination analysis through the use of static dependency pairs.

cs.LO↗