On saturated varieties of posemigroups
We show that a permutative variety of posemigroups satisfying a permutation identity x 1 x 2 ⋯ x n = x i 1 x i 2 ⋯ x i n with i 1 ≠ 1 and i n - 1 ≠ n - 1 [ i n ≠ n and i 2 ≠ 2 ] is saturated if and only if it admits an identity I such that I is not a permutation identity and at least one side of I h...
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Veröffentlicht in: | Algebra universalis 2020-11, Vol.81 (4), Article 48 |
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Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
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Zusammenfassung: | We show that a permutative variety of posemigroups satisfying a permutation identity
x
1
x
2
⋯
x
n
=
x
i
1
x
i
2
⋯
x
i
n
with
i
1
≠
1
and
i
n
-
1
≠
n
-
1
[
i
n
≠
n
and
i
2
≠
2
]
is saturated if and only if it admits an identity
I
such that
I
is not a permutation identity and at least one side of
I
has no repeated variables. Then we show that the variety of po-rectangular bands is saturated. Finally, we show that a posemigroup
S
is saturated if the subposemigroup
S
n
, the product of
n
copies of
S
, is saturated for some positive integer
n
. |
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ISSN: | 0002-5240 1420-8911 |
DOI: | 10.1007/s00012-020-00679-1 |