Un exemple d'ensembles absorbants non équivalents
Tom 140 / 1991
Fundamenta Mathematicae 140 (1991), 49-61
DOI: 10.4064/fm-140-1-49-61
Streszczenie
We give an example in the Hilbert space $ℓ^2$ of two subsets which are absorbing for the class of topologically complete spaces, but for which there exists no homeomorphism of $ℓ^2$ onto itself mapping one of these subsets onto the other.