About: http://webisa.webdatacommons.org/319053738

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	Assume that C is a countable set of countable pairwise disjoint sets, how can we prove that $\cup C$ is countable?
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com