Title of article :
Countable partition ordinals
Author/Authors :
Schipperus، نويسنده , , Rene، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2010
Abstract :
The structure of ordinals of the form ω ω β for countable β is studied. The main result is: Theorem 1
lt; ω 1 is the sum of one or two indecomposable ordinals, then ω ω β → ( ω ω β , 3 ) 2 .
an example is given to show that α → ( α , 3 ) 2 need not imply α → ( α , n ) 2 for all n < ω .
Keywords :
Ordinals , Martin’s axiom , Partition calculus , Set theory , Ramsey Theory
Journal title :
Annals of Pure and Applied Logic
Journal title :
Annals of Pure and Applied Logic