Algebra universalis ( IF 0.6 ) Pub Date : 2022-04-05 , DOI: 10.1007/s00012-022-00773-6 I. B. Kozhuhov 1 , A. M. Pryanichnikov 2
We prove that for any act X over a finite semigroup S, the congruence lattice \({{\,\mathrm{Con}\,}}X\) embeds the lattice \({{\,\mathrm{Eq}\,}}M\) of all equivalences of an infinite set M if and only if X is infinite. Equivalently: for an act X over a finite semigroup S, the lattice \({{\,\mathrm{Con}\,}}X\) satisfies a non-trivial identity if and only if X is finite. Similar statements are proved for an act with zero over a completely 0-simple semigroup \({\mathcal {M}}^0(G,I,\Lambda ,P)\) where \(|G|,|I| <\infty \). We construct examples that show that the assumption \(|G|,|I| <\infty \) is essential.
中文翻译:
在同余格中具有同一性的行为
我们证明对于有限半群S上的任何动作X,同余格\({{\,\mathrm{Con}\,}}X\)嵌入了格\({{\,\mathrm{Eq}\, }}M\)的无限集M的所有等价当且仅当X是无限的。等效地:对于有限半群S上的动作X ,当且仅当X是有限时,格\({{\,\mathrm{Con}\,}}X\)满足非平凡恒等式。对于完全 0-单半群\({\mathcal {M}}^0(G,I,\Lambda ,P)\)上的零行为,类似的陈述被证明,其中\(|G|,|I| < \infty \). 我们构建的例子表明假设\(|G|,|I| <\infty \)是必不可少的。