Complete semi-Thue systems for abelian groups
We show that there are infinitely many examples of finite semi-Thue systems with decidable word problem and which have no finite equivalent noetherian and confluent \((=complete)\) reduction system. These examples have a very simple algebraic structure: they are abelian groups. More precisely, we develop necessary and sufficient conditions for the existence of complete semi-Thue systems for presentations of finitely generated abelian groups.
scientific article; zbMATH DE number 3986634