cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A354493 Number of quantales on n elements, up to isomorphism.

Original entry on oeis.org

1, 2, 12, 129, 1852, 33391, 729629, 19174600, 658343783
Offset: 1

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Author

Arman Shamsgovara, May 28 2022

Keywords

Comments

A quantale is an algebraic structure (X,*,v) composed of a set X of elements, a semigroup operator "*" and a supremum operator "v" (in the sense of lattices) such that * distributes over v: x * (y v z) = (x * y) v (x * z) and (x v y) * z = (x * z) v (y * z) for all elements x,y,z in X. In addition the bottom element corresponding to v, denoted 0, must satisfy x * 0 = 0 * x = 0.

References

  • P. Eklund, J. G. García, U. Höhle, and J. Kortelainen, (2018). Semigroups in complete lattices. In Developments in Mathematics (Vol. 54). Springer Cham.
  • K. I. Rosenthal, Quantales and their applications. Longman Scientific and Technical, 1990.
  • Arman Shamsgovara, A catalogue of every quantale of order up to 9 (abstract, to appear), LINZ2022, 39th Linz Seminar on Fuzzy Set Theory, Linz, Austria.
  • Arman Shamsgovara and P. Eklund, A Catalogue of Finite Quantales, GLIOC Notes, December 2019.

Crossrefs

Related algebraic structures: A027851, A006966.

Programs

  • Mace4
    assign(max_models,-1).
    assign(domain_size,4).
    formulas(assumptions).
    % Comment: This will find all quantales on 4 elements, fixing
    % 0 as the bottom and 3 as the top. Elements will be numbered
    % 0-3. Results *must* be run through the companion program
    % isofilter that is included with the downloads for mace4,
    % otherwise the output will contain isomorphic duplicates!
    % By changing the domain size, this file should be sufficient
    % for up to 6 elements, but will crash for higher numbers.
    (x*y)*z = x*(y*z).
    (x v y) v z = x v (y v z).
    x v y = y v x.
    x v x = x.
    x*(y v z) = (x*y) v (x*z).
    (x v y)*z = (x*z) v (y*z).
    0*x = 0.
    x*0 = 0.
    0 v x = x.
    3 v x = 3.
    end_of_list.
    formulas(goals).
    end_of_list.