Abstract
An algebraic structure A is said to be finitely subdirectly reducible if A is not finitely subdirectly irreducible. We show that for any signature providing only finitely many relation symbols, the class of finitely subdirectly reducible algebraic structures is closed with respect to the formation of ultraproducts. We provide some corollaries and examples for axiomatizable classes that are closed with respect to the formation of finite subdirect products, in particular, for varieties and quasivarieties.
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Presented by R. Willard.
The research was supported by Ministry of Education and Sciences of Kazakhstan, grant 3953/GF4.
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Nurakunov, A.M. Ultraproducts preserve finite subdirect reducibility. Algebra Univers. 78, 181–192 (2017). https://doi.org/10.1007/s00012-017-0450-3
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DOI: https://doi.org/10.1007/s00012-017-0450-3