A set function μ is said to possess finite subadditivity if, given any finite disjoint collection of sets {E_k}_(k = 1)^n on which μ is defined, μ( union _(k = 1)^n E_k)<= sum_(k = 1)^n μ(E_k). A set function possessing finite subadditivity is said to be finitely subadditive. In particular, every finitely additive set function μ is also finitely subadditive.

countable additivity | countable subadditivity | disjoint union | finite additivity | set function