We define semantically a partial multiplication on the lattice of all e–varieties of regular semigroups. In the case that the first factor is an e–variety of orthodox semigroups we describe our multiplication syntactically in terms of biinvariant congruences.
@article{107523,
author = {Martin Ku\v ril},
title = {A multiplication of $e$-varieties of orthodox semigroups},
journal = {Archivum Mathematicum},
volume = {031},
year = {1995},
pages = {43-54},
zbl = {0836.20084},
mrnumber = {1342374},
language = {en},
url = {http://dml.mathdoc.fr/item/107523}
}
Kuřil, Martin. A multiplication of $e$-varieties of orthodox semigroups. Archivum Mathematicum, Tome 031 (1995) pp. 43-54. http://gdmltest.u-ga.fr/item/107523/
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