Radon's theorem

Theorem (Radon, 1921)

Any set of $d+2$ points in $\mathbb{R}^d$ can be partitioned into two sets whose convex hulls intersect

(see reals $\mathbb{R}$)

References

1. https://en.wikipedia.org/wiki/Radon's_theorem
2. https://sarielhp.org/book/chapters/vc_dim.pdf
3. J. Radon, “Mengen konvexer Körper, die einen gemeinsamen Punkt enthalten,” Math. Ann., vol. 83, no. 1–2, pp. 113–115, Mar. 1921, doi: 10.1007/BF01464231.