Two Results on Separation Logic With Theory Reasoning

TL;DR

This paper proves that the entailment problem in Separation Logic with theory reasoning is undecidable for rules with bounded tree-width, but also shows it can be reduced to a form without equality, advancing understanding of its computational limits.

Contribution

It establishes undecidability of the entailment problem under certain conditions and provides a reduction to an equality-free form, broadening theoretical insights.

Findings

Entailment problem is undecidable for rules with bounded tree-width with theory reasoning.

Any entailment problem can be reduced to an equality-free form.

Results apply to theories like natural numbers with successor or order.

Abstract

Two results are presented concerning the entailment problem in Separation Logic with inductively defined predicate symbols and theory reasoning. First, we show that the entailment problem is undecidable for rules with bounded tree-width, if theory reasoning is considered. The result holds for a wide class of theories, even with a very low expressive power. For instance it applies to the natural numbers with the successor function, or with the usual order. Second, we show that every entailment problem can be reduced to an entailment problem containing no equality (neither in the formulas nor in the recursive rules defining the semantics of the predicate symbols).