Reflexive Graphs with Near Unanimity but no Semilattice Polymorphisms
نویسندگان
چکیده
منابع مشابه
Reflexive digraphs with near unanimity polymorphisms
In this paper we prove that if a finite reflexive digraph admits Gumm operations, then it also admits a near unanimity operation. This is a generalization of similar results obtained earlier for posets and symmetric reflexive digraphs by the second author and his collaborators. In the special case of reflexive digraphs our new result confirms a conjecture of Valeriote that states that any finit...
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ژورنال
عنوان ژورنال: The Electronic Journal of Combinatorics
سال: 2018
ISSN: 1077-8926
DOI: 10.37236/6196