How many clouds cover the plane?
Volume 177 / 2003
Fundamenta Mathematicae 177 (2003), 209-211
MSC: 03E50, 51M05.
DOI: 10.4064/fm177-3-2
Abstract
The plane can be covered by $n+2$ clouds iff $2^{\aleph _0} \leq \aleph _n$.
