Abstract
Subdirect representations are investigated in varieties which are defined by operations of not necessarily finite arity. It is shown that, in this context, Birkhoff's Subdirect Representation Theorem does not hold. However, a class of unranked varieties is identified which admit subdirect representations by subdirectly irreducibles and are even residually small.
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Porst, HE. Residually Small Varieties Without Rank. Applied Categorical Structures 12, 355–360 (2004). https://doi.org/10.1023/B:APCS.0000040385.40141.da
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DOI: https://doi.org/10.1023/B:APCS.0000040385.40141.da