论文标题
Galvin关于非$σ$的问题 - 订购的线性订单
Galvin's Question on non-$σ$-Well Ordered Linear Orders
论文作者
论文摘要
假设$ \ MATHCAL {C} $是所有线性订单$ L $的类，因此$ L $不是订购良好的集合的可数联合，并且每个不可数的子集的$ L $都包含$ω_1$的副本。我们表明，$ \ Mathcal {C} $具有最小的元素是一致的。这回答了由于Galvin引起的一个旧问题。
Assume $\mathcal{C}$ is the class of all linear orders $L$ such that $L$ is not a countable union of well ordered sets, and every uncountable subset of $L$ contains a copy of $ω_1$. We show it is consistent that $\mathcal{C}$ has minimal elements. This answers an old question due to Galvin.
