In this paper, we introduce monoidal rewriting systems (MRS), an abstraction of string rewriting in which reductions are defined over an arbitrary ambient monoid rather than a free monoid of words. This shift is partly motivated by logic: the class of free monoids is not first-order axiomatizable, so "working in the free setting" cannot be treated internally when applying first-order methods to rewriting presentations. To analyze these systems categorically, we define $\mathbf{NCRS_2}$ as the 2-category of Noetherian Confluent MRS. We then prove the existence of a canonical biadjunction between $\mathbf{NCRS_2}$ and $\mathbf{Mon}$. Finally, we classify all Noetherian Confluent MRS that present a given fixed monoid. For this, we introduce Generalized Elementary Tietze Transformations (GETTs) and prove that any two presentations of a monoid are connected by a (possibly infinite) sequence of these transformations, yielding a complete characterization of generating systems up to GETT-equivalence.
翻译:本文引入幺半群重写系统(MRS),这是字符串重写的一种抽象,其中归约定义在任意环境幺半群上,而非自由幺半群的词上。这一转变部分源于逻辑动机:自由幺半群类不是一阶可公理化的,因此在应用一阶方法处理重写表示时,“在自由设定下工作”无法在内部处理。为从范畴角度分析这些系统,我们定义 $\mathbf{NCRS_2}$ 为诺特合流 MRS 的 2-范畴。随后证明 $\mathbf{NCRS_2}$ 与 $\mathbf{Mon}$ 之间存在典范双伴随关系。最后,我们对所有呈现给定固定幺半群的诺特合流 MRS 进行分类。为此,我们引入广义初等蒂策变换(GETT),并证明幺半群的任意两个表示均可通过(可能无限的)此类变换序列相互连接,从而在 GETT 等价意义下完整刻画了生成系统。