Poset algebras over well quasi-ordered posets

Uri Abraham, Robert Bonnet, Wiesław Kubiś

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

A new class of partial order-types, class G+ bqo is defined and investigated here. A poset P is in the class G+_ iff the poset algebra F(P) is generated by a better quasi-order G that is included in L(P). The free Boolean algebra F(P) and its free distributive lattice L(P) have been defined in [ABKR]. The free Boolean algebra F(P) contains the partial order P and is generated by it: F(P) has the following universal property. If B is any Boolean algebra and f is any order-preserving map from P into a Boolean algebra B, then f can be extended to a homomorphism f of F(P) into B. We also define L(P) as the sublattice of F(P) generated by P. We prove that if P is any well quasi-ordering, then L(P) is well founded, and is a countable union of well quasi-orderings. We prove that the class G+_bqo is contained in the class of well quasi-ordered sets. We prove that G+_bqo is preserved under homomorphic image, finite products, and lexicographic sum over better quasi-ordered index sets. We prove also that every countable well quasi-ordered set is in G+bqo. We do not know, however if the class of well quasi-ordered sets is contained in G+_bqo . Additional results concern homomorphic images of posets algebras.

Original languageEnglish
Pages (from-to)263-286
Number of pages24
JournalAlgebra Universalis
Volume58
Issue number3
DOIs
StatePublished - 1 Jun 2008

Keywords

  • Better quasi-orderings (bqo)
  • Poset algebras
  • Superatomic Boolean algebras
  • Well quasi-orderings (wqo)

ASJC Scopus subject areas

  • Algebra and Number Theory
  • Logic

Fingerprint

Dive into the research topics of 'Poset algebras over well quasi-ordered posets'. Together they form a unique fingerprint.

Cite this