Inscribing compact non--porous sets into analytic non-\sigma-porous sets
Tom 185 / 2005
Fundamenta Mathematicae 185 (2005), 19-39
MSC: 54H05, 28A05.
DOI: 10.4064/fm185-1-2
Streszczenie
The main aim of this paper is to give a simpler proof of the following assertion. Let A be an analytic non-\sigma-porous subset of a locally compact metric space ,E. Then there exists a compact non-\sigma-porous subset of A. Moreover, we prove the above assertion also for \sigma-\bf P-porous sets, where {\bf P} is a porosity-like relation on E satisfying some additional conditions. Our result covers \sigma-\langle g \rangle-porous sets, \sigma-porous sets, and \sigma-symmetrically porous sets.
