On the connection between the theorems of Gleason and of Kochen and Specker

We present an elementary proof of a reduced version of Gleason’s theorem and the Kochen-Specker theorem to provide a novel perspective on the relation between both theorems. The proof is based on a set of linear equations for the values of a function $m$ on the unit sphere. In the case of Gleason’s theorem the entire unit sphere needs to be considered, while a finite set of points suffices to prove the Kochen-Specker theorem.