10 citations · 35 across the 7 of their papers we have counts for
8 papers
Transposition of variables is hard to describe
H. Andréka, I. Németi, Zs. Tuza
The function that interchanges two logical variables in formulas is hard to describe in the following sense. Let denote the Lindenbaum-Tarski formula-algebra of…
Varieties generated by completions
H. Andréka, I. Németi
We prove that persistently finite algebras are not created by completions of algebras, in any ordered discriminator variety. A persistently finite algebra is one without infinite s…
Nonrepresentable relation algebras from group systems
H. Andréka, S. Givant, I. Németi
A series of nonrepresentable relation algebras is constructed from groups. We use them to prove that there are continuum many subvarieties between the variety of representable rela…
A representation theorem for measurable relation algebras
S. Givant, H. Andréka
A relation algebra is called measurable when its identity is the sum of measurable atoms, and an atom is called measurable if its square is the sum of functional elements. In this…
The variety of coset relation algebras
Steven Givant, Hajnal Andréka
A coset relation algebra is one embeddable into some full coset relation algebra, the latter is an algebra constructed from a system of groups, a coordinated system of isomorphisms…
Coset relation algebras
H. Andréka, S. Givant
A measurable relation algebra is a relation algebra in which the identity element is a sum of atoms that can be measured in the sense that the "size" of each such atom can be defin…