TY  - JOUR
A1  - Tinpun, Kittisak
A1  - Koppitz, Jörg
T1  - Generating sets of infinite full transformation semigroups with restricted range
JF  - Acta scientiarum mathematicarum
N2  - In the present paper, we consider minimal generating sets of infinite full transformation semigroups with restricted range modulo specific subsets. In particular, we determine relative ranks.
KW  - generating sets
KW  - transformation semigroups
KW  - restricted range
KW  - relative ranks
Y1  - 2016
U6  - https://doi.org/10.14232/actasm-015-502-4
SN  - 0001-6969
VL  - 82
SP  - 55
EP  - 63
PB  - Institutum Bolyaianum Universitatis Szegediensis
CY  - Szeged
ER  - 
TY  - JOUR
A1  - Shtrakov, Slavcho
A1  - Koppitz, Jörg
T1  - Stable varieties of semigroups and groupoids
JF  - Algebra universalis
N2  - The paper deals with Sigma-composition and Sigma-essential composition of terms which lead to stable and s-stable varieties of algebras. A full description of all stable varieties of semigroups, commutative and idempotent groupoids is obtained. We use an abstract reduction system which simplifies the presentations of terms of type tau - (2) to study the variety of idempotent groupoids and s-stable varieties of groupoids. S-stable varieties are a variation of stable varieties, used to highlight replacement of subterms of a term in a deductive system instead of the usual replacement of variables by terms.
KW  - composition of terms
KW  - essential position in terms
KW  - stable variety
Y1  - 2016
U6  - https://doi.org/10.1007/s00012-015-0359-7
SN  - 0002-5240
SN  - 1420-8911
VL  - 75
SP  - 85
EP  - 106
PB  - Springer
CY  - Basel
ER  -