linguistic:voice_change
Whitehead's axioms

These axioms are based on Whitehead, "The Axioms of Projective Geometry". There are two types, points and lines, and one "incidence" relation between points and lines. The three axioms are:

The reason each line is assumed to contain at least 3 points is to eliminate some degenerate cases. The spaces satisfying thesethree axioms either have at most one line, or are projective spaces of some dimension over a division ring, or are non-Desarguesian planes.