Jónsson's theorem in non-modular varieties. (Q1771886)
From MaRDI portal
scientific article
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | Jónsson's theorem in non-modular varieties. |
scientific article |
Statements
Jónsson's theorem in non-modular varieties. (English)
0 references
19 April 2005
0 references
Jónsson's Lemma says that if \(HSP(\mathcal K)\) is congruence distributive and \(B\in HSP(\mathcal K)\) is subdirectly irreducible then \(B\in HSP_u(\mathcal K)\). It was generalized in 80s by Hagemann, Hermann, Freese, McKenzie and Hrushovski: If \(HSP(\mathcal K)\) is congruence modular and \(B\in HSP(\mathcal K)\) is subdirectly irreducible and \(\alpha \) is the centralizer of the monolith of \(B\), then \(B/\alpha \in HSP_u(\mathcal K)\). The present author dropped out the assumption of congruence modularity and proves: Let \(B\) be a subdirectly irreducible algebra in \(HSP(\mathcal K)\) and let \(\alpha \) be a maximal congruence that laxly centralizes the monolith of \(B\). Then \(B/\alpha \in HSP_u(\mathcal K)\).
0 references
centralizer
0 references
commutator
0 references
Jónsson's Lemma
0 references