arXiv subjects

Aljoscha Windhorst

Publications and source records attributed to Aljoscha Windhorst.

2 recordsLinked to original sources

arXiv2023

Moving a Derivation Along a Derivation Preserves the Spine in Adhesive Categories

In this paper, we investigate the relationship between two elementary operations on derivations in the framework of graph transformation based on adhesive categories: moving a derivation along a derivation based on parallel and sequential independence on one hand and restriction of a derivation with respect to a monomorphism into the start object on the other hand. Intuitively, a restriction clips off parts of the start object that are never matched by a rule application throughout the derivation on the other hand. As main result, it is shown that moving a derivation preserves its spine being the minimal restriction.

cs.DM↗

arXiv2022

A Graph-Transformational Approach for Proving the Correctness of Reductions between NP-Problems

The complexity class NP of decision problems that can be solved nondeterministically in polynomial time is of great theoretical and practical importance where the notion of polynomial-time reductions between NP-problems is a key concept for the study of NP. As many typical NP-problems are naturally described as graph problems, they and their reductions are obvious candidates to be investigated by graph-transformational means. In this paper, we propose such a graph-transformational approach for proving the correctness of reductions between NP-problems.

cs.CC↗