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APAL
2006
45views more  APAL 2006»
13 years 11 months ago
On properties of theories which preclude the existence of universal models
We introduce the oak property of first order theories, which is a syntactical condition that we show to be sufficient for a theory not to have universal models in cardinality whe...
Mirna Dzamonja, Saharon Shelah
APAL
2008
77views more  APAL 2008»
13 years 11 months ago
More on SOP1 and SOP2
This paper continues [Sh500] and [DzSh692]. We present a rank function for NSOP1 theories and give an example of a theory which is NSOP1 but not simple. We also investigate the con...
Saharon Shelah, Alexander Usvyatsov
AML
2008
53views more  AML 2008»
13 years 11 months ago
Pairs, sets and sequences in first-order theories
In this paper we study the idea of theories with containers, like sets, pairs, sequences. We provide a modest framework to study such theories. We prove two concrete results. Firs...
Albert Visser
AML
2010
99views more  AML 2010»
13 years 11 months ago
Effectively inseparable Boolean algebras in lattices of sentences
We show the non-arithmeticity of 1st order theories of lattices of n sentences modulo provable equivalence in a formal theory, of diagonalizable algebras of a wider class of arithm...
V. Yu. Shavrukov
CIE
2009
Springer
14 years 3 months ago
The First Order Theories of the Medvedev and Muchnik Lattices
We show that the first order theories of the Medevdev lattice and the Muchnik lattice are both computably isomorphic to the third order theory of the natural numbers.
Andrew Lewis, André Nies, Andrea Sorbi