Monoidal intervals of clones on infinite sets

نویسنده

  • Michael Pinsker
چکیده

Let X be an infinite set of cardinality κ. We show that if L is an algebraic and dually algebraic distributive lattice with at most 2 completely join irreducibles, then there exists a monoidal interval in the clone lattice on X which is isomorphic to the lattice 1 + L obtained by adding a new smallest element to L. In particular, we find that if L is any chain which is an algebraic lattice, and if L does not have more than 2 completely join irreducibles, then 1+L appears as a monoidal interval; also, if λ ≤ 2, then the power set of λ with an additional smallest element is a monoidal interval. Concerning cardinalities of monoidal intervals these results imply that there are monoidal intervals of all cardinalities not greater than 2, as well as monoidal intervals of cardinality 2, for all λ ≤ 2.

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عنوان ژورنال:
  • Discrete Mathematics

دوره 308  شماره 

صفحات  -

تاریخ انتشار 2008