We show that limit varieties of monoids recently discovered by Gusev, Zhang and Luo and their subvarieties are generated by monoids of the form \(M_\tau (W)\) for certain congruences \(\tau \) on the free monoid. The construction \(M_\tau (W)\) is a generalization of widely used Dilworth–Perkins construction. Using this construction, we find explicit generators for Gusev limit varieties and give a short reproof to the fact that Zhang–Luo limit variety is non-finitely based.

中文翻译：

---

J-平凡半群的极限变体

我们显示了Gusev，Zhang和Luo最近发现的类limit虫的极限变体及其子变体是由形式为\（M_ \ tau（W）\）的类id虫生成的，这些类mono对自由类id虫的某些等价\（\ tau \）。结构\（M_tau（W）\）是广泛使用的Dilworth–Perkins结构的推广。使用这种构造，我们找到了Gusev极限变型的显式​​生成器，并简短地证明了张罗极限变型是非有限的。