Abstract
Idempotent slim groupoids are groupoids satisfying xx ≈ x and x(yz) ≈ xz. We prove that the variety of idempotent slim groupoids has uncountably many subvarieties. We find a four-element, inherently nonfinitely based idempotent slim groupoid; the variety generated by this groupoid has only finitely many subvarieties. We investigate free objects in some varieties of idempotent slim groupoids determined by permutational equations.
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The work is a part of the research project MSM0021620839 financed by MSMT and partly supported by the Grant Agency of the Czech Republic, grant #201/05/0002.
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Ježek, J. Varieties of idempotent slim groupoids. Czech Math J 57, 1289–1309 (2007). https://doi.org/10.1007/s10587-007-0124-y
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DOI: https://doi.org/10.1007/s10587-007-0124-y