Saturation, Suslin trees and meager sets
β Scribed by Paul Larson
- Publisher
- Springer
- Year
- 2004
- Tongue
- English
- Weight
- 190 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0933-5846
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
The supremum of the symmetric difference x y := (x \ y) βͺ (y \ x) of subsets x, y of R satisfies the so-called four-point condition; that is, for all x, x , y, y β R, one has It follows that the set E of all subsets of R which are bounded from above forms a valuated matroid relative to the map v:
For any tree T, it is proved that 0(T), the smallest cardinality of a perfect neighbourhood set, is bounded above by ir(T), the smallest cardinality of a maximal irredundant set.
Let f be a continuous map of a tree X into itself. Let Q(j) denote the set of nonwandering points for f. In this paper we show the following two results: (1) if C?(f) is finite then Q(f) is the set of periodic points of f, (2) Q(f) IS contained in the closure of the set of eventually periodic points