Characterization of $\sigma $-porosity via an infinite game
Volume 216 / 2012
Fundamenta Mathematicae 216 (2012), 109-118
MSC: 28A05.
DOI: 10.4064/fm216-2-2
Abstract
Let $X$ be an arbitrary metric space and $P$ be a porosity-like relation on $X$. We describe an infinite game which gives a characterization of $\sigma $-$P$-porous sets in $X$. This characterization can be applied to ordinary porosity above all but also to many other variants of porosity.
