Discussiones
Mathematicae General Algebra and Applications 22(1) (2002) 87100
doi: 10.7151/dmgaa.1049
EQUATIONAL BASES FOR WEAK MONOUNARY VARIETIES
Grzegorz Bińczak
Institute of Mathematics, Warsaw University of Technology
pl. Politechniki 1, 00661 Warszawa, Poland
email: binczak@mini.pw.edu.pl
Abstract
It is wellknown that every monounary variety of total algebras has oneelement equational basis (see [5]).
In my paper I prove that every monounary weak variety has at most 3element equational basis. I give an
example of monounary weak variety having 3element equational basis, which has no 2element equational basis.
Keywords: partial algebra, weak equation, weak variety, regular equation, regular weak equational
theory, monounary algebras.
2000 AMS Mathematics Subject Classifications: 08A55, 08B05.
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Received 19 April 2002
Revised 2 July 2002