Additive set function

Dependencies:

  1. Set function

A set function $f: 2^Ω → ℝ$ is additive iff $f(A ∪ B) = f(A) + f(B)$ for all disjoint sets $A$ and $B$.

If $f$ is additive, then $f(∅) = 0$, since $f(∅) = f(∅ ∪ ∅) = f(∅) + f(∅)$.

If $Ω$ is discrete, then $f(S) = \sum_{e ∈ S} f(e)$ for all $S ⊆ Ω$.

Dependency for:

  1. A set function is additive iff it is submodular and supermodular iff it is subadditive and superadditive.
  2. Cake cutting: PROP implies EEF for additive valuations
  3. EFX implies EF1
  4. EEF doesn't imply EF for additive valuations

Info:

Transitive dependencies:

  1. /sets-and-relations/countable-set
  2. σ-algebra
  3. Set function