# On the lattice of sub-pseudovarieties of DA

@article{Kufleitner2009OnTL,
title={On the lattice of sub-pseudovarieties of DA},
author={Manfred Kufleitner and Pascal Weil},
journal={Semigroup Forum},
year={2009},
volume={81},
pages={243-254}
}
• Published 19 April 2009
• Mathematics
• Semigroup Forum
The wealth of information that is available on the lattice of varieties of bands, is used to illuminate the structure of the lattice of sub-pseudovarieties of DA, a natural generalization of bands which plays an important role in language theory and in logic. The main result describes a hierarchy of decidable sub-pseudovarieties of DA in terms of iterated Mal’cev products with the pseudovarieties of definite and reverse definite semigroups.
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