Additivity of a cooperative-game value
= Additivity of a cooperative-game value
{title2=$\psi(v+w)=\psi(v)+\psi(w)$}
= Cooperative-game additivity
{synonym}
A value has <cooperative-game additivity> when adding two characteristic <functions> on the same player <set> adds their allocation <vectors>. Here $(v+w)(S)=v(S)+w(S)$ for every <coalition>. The sum of two <simple cooperative games> need not be simple; the axiom is naturally stated on <transferable utility games>.