Equational definability of (complementary) central elements
Mariana V. Badano, Diego Vaggione · International Journal of Algebra and Computation · 2016
For a variety with weak existentially definable factor congruences, we characterize when the properties “[Formula: see text] is a central element” and “[Formula: see text] and [Formula: see text] are complementary central elements” are definable by [Formula: see text]-formulas and by [Formula: see text]-formulas.