On a Construction of J. Tkadlec, Concerning σ-Porous Sets

Abstract

n the paper [2] Josef Tkadlec gave an example of a finite singular Borel measure $\mu$ on the real line such that all $\sigma$-porous sets are of $\mu$-measure zero. We give an alternative proof, i.e. probably a simpler construction, of his theorem [2, theorem] and we also give a similar example in $\mathbb{R}^n.