Planar semilattices and nearlattices with eighty-three subnearlattices
نویسندگان
چکیده
منابع مشابه
Semilattices of Breadth Three
A 1984 problem of S. Z. Ditor asks whether there exists a lattice of cardinality א2, with zero, in which every principal ideal is finite and every element has at most three lower covers. We prove that the existence of such a lattice follows from either one of two axioms that are known to be independent of ZFC, namely (1) Martin’s Axiom restricted to collections of א1 dense subsets in posets of ...
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A 1984 problem of S. Z. Ditor asks whether there exists a lattice of cardinality א2, with zero, in which every principal ideal is finite and every element has at most three lower covers. We prove that the existence of such a lattice follows from either one of two axioms that are known to be independent of ZFC, namely (1) Martin’s Axiom restricted to collections of א1 dense subsets in posets of ...
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چکیده ندارد.
Semilattices and Ramsey Property
We consider S, the class of nite semilattices; T , the class of nite treeable semilattices; and Tm, the subclass of T which contains trees with branching bounded by m. We prove that ES, the class of nite lattices with linear extensions, is a Ramsey class. We calculate Ramsey degrees for structures in S, T and Tm. In addition to this we give a topological interpretation of our results and we ...
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ژورنال
عنوان ژورنال: Acta Scientiarum Mathematicarum
سال: 2020
ISSN: 0001-6969
DOI: 10.14232/actasm-019-573-4