324 citations · 1.7k across the 753 of their papers we have counts for
14 papers · 1 filter
A dichotomy for the number of ultrapowers
Ilijas Farah, Saharon Shelah
We prove a strong dichotomy for the number of ultrapowers of a given countable model associated with nonprincipal ultrafilters on N. They are either all isomorphic, or else there a…
Uniform n-place functions on T\subseteq ds(α)
Esther Gruenhut, Saharon Shelah
In this paper the Erdos-Rado theorem is generalized to the class of well founded trees. We define an equivalence relation on the class rs(infty)^{< aleph_0} (finite sequences of de…
Stable theories and representation over sets
Moran Cohen, Saharon Shelah
In this paper we explore the representation property over sets. This property generalizes constructibility, however is weak enough to enable us to prove that the class of theories…
More on the pressing down game
Jakob Kellner, Saharon Shelah
We investigate the pressing down game and its relation to the Banach Mazur game. In particular we show: Consistently, there is a nowhere precipitous normal ideal on …
PCF arithmetic without and with choice
Saharon Shelah
We deal with relatives of GCH which are provable. In particular we deal with rank version of the revised GCH. Our motivation was to find such results when only weak versions of the…
Nonproper Products
Andrzej Roslanowski, Saharon Shelah, Otmar Spinas
We show that there exist two proper creature forcings having a simple (Borel) definition, whose product is not proper. We also give a new condition ensuring properness of some forc…