The separating axis theorem (SAT) says that: Technically a separating axis is never unique because it can be translated in the second version of the theorem, a separating axis can be unique up to translation. In the second version, it may or may not be unique. In the first version of the theorem, evidently the separating hyperplane is never unique. For example, A can be a closed square and B can be an open square that touches A. (Although, by an instance of the second theorem, there is a hyperplane that separates their interiors.) Another type of counterexample has A compact and B open. In the context of support-vector machines, the optimally separating hyperplane or maximum-margin hyperplane is a hyperplane which separates two convex hulls of points and is equidistant from the two. The HahnвЂ“Banach separation theorem generalizes the result to topological vector spaces.ДЄ related result is the supporting hyperplane theorem. The hyperplane separation theorem is due to Hermann Minkowski. An axis which is orthogonal to a separating hyperplane is a separating axis, because the orthogonal projections of the convex bodies onto the axis are disjoint. In another version, if both disjoint convex sets are open, then there is a hyperplane in between them, but not necessarily any gap. In one version of the theorem, if both these sets are closed and at least one of them is compact, then there is a hyperplane in between them and even two parallel hyperplanes in between them separated by a gap.

There are several rather similar versions. In geometry, the hyperplane separation theorem is a theorem about disjoint convex sets in n-dimensional Euclidean space.

Hyperplan entre deux points