3 citations · 6 across the 5 of their papers we have counts for
5 papers
Relation algebras and groups
Steven Givant
Generalizing results of Jónsson and Tarski, Maddux introduced the notion of a pair-dense relation algebra and proved that every pair-dense relation algebra is representable. The no…
Term algebras of elementarily equivalent atom structures
H. Andréka, I. Németi
We exhibit two relation algebra atom structures such that they are elementarily equivalent but their term algebras are not. This answers Problem 14.19 in the book Hirsch, R. and Ho…
Finite-variable logics do not have weak Beth definability property
H. Andréka, I. Németi
We prove that n-variable logics do not have the weak Beth definability property, for all n greater than 2. This was known for n=3 (Ildikó Sain and András Simon), and for n greater…
An Axiom System for General Relativity Complete with respect to Lorentzian Manifolds
Hajnal Andréka, Judit X. Madarász, István Németi +1
We introduce several axiom systems for general relativity and show that they are complete with respect to the standard models of general relativity, i.e., to Lorentzian manifolds h…
What are the numbers in which spacetime?
H. Andréka, J. X. Madarász, I. Németi +1
Within an axiomatic framework, we investigate the possible structures of numbers (as physical quantities) in different theories of relativity.