1. Subdirect products of certain varieties of unary algebras
- Creator:
- Ćirić, Miroslav, Petković, Tatjana, and Bogdanović, Stojan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- unary algebra, subdirect product, variety, and directable algebra
- Language:
- English
- Description:
- J. Płonka in [12] noted that one could expect that the regularization ${\mathcal R}(K)$ of a variety ${K}$ of unary algebras is a subdirect product of ${K}$ and the variety ${D}$ of all discrete algebras (unary semilattices), but is not the case. The purpose of this note is to show that his expectation is fulfilled for those and only those irregular varieties ${K}$ which are contained in the generalized variety ${TDir}$ of the so-called trap-directable algebras.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public