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On the weight of compact retracts - MaRDI portal

On the weight of compact retracts (Q1123435)

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scientific article; zbMATH DE number 4109601
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English
On the weight of compact retracts
scientific article; zbMATH DE number 4109601

    Statements

    On the weight of compact retracts (English)
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    1988
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    For an infinite cardinal number \(\tau\) the class \(AN_{\tau}R\) is defined as follows: Let \(X\) be a compact topological space. Then, \(X\in AN_{\tau}R\) if and only if for every compact \(Y\supset X\) there exists \(Z\) such that \(X\subset Z\subset Y\), the set \(X\) is a retract of \(Z\), and \(Z\) is the intersection of a family \({\mathcal U}\) of open sets with \(\mathrm{card}\,{\mathcal U}=\tau\). The authors give a characterization of \(AN_{\tau}R\)'s as inverse limits of some inverse systems of compact spaces with weight at most \(\tau\). As a corollary they obtain characterizations of compact spaces of weight at most \(\tau\) as \(AN_{\tau}R\)'s satisfying some additional conditions. \{On the page 96 line 17 from the bottom for \(X_ 0\) read \(X_{\alpha}.\}\)
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    absolute neighbourhood retract
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    inverse limits
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    weight
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