We provide details for a Theorem which is only available on a unfinished preliminary draft of P. Nyikos: the existence under of a hereditarily collectionwise normal countably compact non-compact manifold which does not contain a copy of . This shows in particular that {\bf MA + CH} does not imply the existence of a copy of in a countably compact non-compact manifold (it is known that {\bf PFA} does imply it). The said manifold is obtained from a principal -bundle over the long ray, and some structural Theorems for these spaces (due to Nyikos as well) are also proved. We show that the same type of theorems hold for -to- closed preimages of and -``bundles’’ over , where is the additive group of integers modulo . A small generalization of is also quickly investigated.

生成讲解博客的中文版本

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