On Equational Theories of Semilattices with Operators
نویسنده
چکیده
The question of characterizing the lattices of subvarieties of a variety of universal algebras seems to be very difficult. Some years ago a conjecture was that a lattice is isomorphic to the lattice of all extensions of an equational theory (or dually isomorphic to the lattice of subvarieties of a variety) iff it is algebraic and its greatest element is compact. In [2] and [3] W. Lampe proved this to be false and found further conditions that such a lattice must satisfy. The purpose of the present paper is to find a class K of lattices with the following properties:
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تاریخ انتشار 2011