Timeline for Uncountable divisible groups and the existence of order-preserving isomorphisms of their subsets
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
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| Nov 5, 2016 at 9:58 | comment | added | shane.orourke | It follows from the fact that $\omega_1$ has no countable cofinal subset (since it is the first uncountable ordinal). Now for a non-zero element a of A let $\alpha_a$ be its first non-zero entry. Since A is cofinal in $G^{<0}$, the set of such $\alpha_a$ is cofinal in $\omega_1$, a contradiction. | |
| Nov 4, 2016 at 21:31 | comment | added | N.W. | I do not understand, why there is no countable cofinal subset in $G^{<0}$? | |
| Jul 29, 2016 at 7:05 | vote | accept | N.W. | ||
| Jul 27, 2016 at 22:11 | history | answered | shane.orourke | CC BY-SA 3.0 |