Separation theorem: If the nonempty sets S and F are convex sets and have no interior points of the same * * * *, then there is a straight line L: px = b to separate the sets S and F, and there are:

I)px≤b, any x ∈ s;

Ii)px≥b, any x ∈ f.

When the selected variable is three-dimensional, the straight line L: px = b is a plane, which is called the separation plane. When there are more than three dimensions, it is called separation hyperplane.