  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.

Quantum Physics