About: http://webisa.webdatacommons.org/442171578

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Yet, I am wondering if there is an example of a finite union-closed family $F$ such that the set of elements that belong to at least half the sets of $F$ does not contain any member of $F$?
http://www.w3.org/ns/prov#wasQuotedFrom	mathoverflow.net