Abstract
We deal with incompactness. Assume the existence of non-reflecting stationary set of cofinality κ. We prove that one can define a graph G whose chromatic number is >κ, while the chromatic number of every subgraph G′{subset double equals}G, {pipe}G′{pipe}<{pipe}G{pipe} is ≦κ. The main case is κ=א0.
Original language | English |
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Pages (from-to) | 363-371 |
Number of pages | 9 |
Journal | Acta Mathematica Hungarica |
Volume | 139 |
Issue number | 4 |
DOIs | |
State | Published - Jun 2013 |
Keywords
- 03E05
- 05C15
- chromatic number
- compactness
- graph
- non-reflecting stationary set
- set theory