Product preservation and stable units for reflections into idempotent subvarieties
نویسندگان
1 Department of Mathematics, University of Aveiro, Portugal.
2 CIDMA - Center for Research and Development in Mathematics and Applications, Department of Mathematics, University of Aveiro, Portugal.
doi
10.29252/cgasa.13.1.1چکیده
We give a necessary and sufficient condition for the preservation of finite products by a reflection of a variety of universal algebras into an idempotent subvariety. It is also shown that simple and semi-left-exact reflections into subvarieties of universal algebras are the same. It then follows that a reflection of a variety of universal algebras into an idempotent subvariety has stable units if and only if it is simple and the above-mentioned condition holds.
