411 REFERENCE · Wikibooks
Geometry/Neutral Geometry/Incidence Geometry
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Incidence Axioms
Incidence Axiom 1
For every point P and for every point Q not equal to P, there exists a unique line l incident with P and Q.
Incidence Axiom 2
For every line l, there exists at least two distinct points incident with l
Incidence Axiom 3
There exists three distinct points with the property that no line is incident with all three of them