Definability of small puncture sets
Tom 215 / 2011
Fundamenta Mathematicae 215 (2011), 39-51
MSC: Primary 03E15; Secondary 28A05.
DOI: 10.4064/fm215-1-2
Streszczenie
We characterize the class of definable families of countable sets for which there is a single countable definable set intersecting every element of the family.