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Article

Keywords:
Lindelöf degree; $G_\delta$ topology; cardinal functions
Summary:
We establish a relation between covering properties (e.g\. Lindelöf degree) of two standard topological spaces (Lemmas 4 and 5). Some cardinal inequalities follow as easy corollaries.
References:
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[4] Juhàsz I.: On closed discrete subspaces of product spaces. Bull. Acad. Pol., vol.XVII, no.4, 1969. MR 0254808
[5] Todorcevi\`c S.: Incompactness of $\Bbb N^\theta$. Handwritten notes, 1990.
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