Axiom:Identity of Betweenness

Axiom
Let $a$ and $b$ be points.

Let $\mathsf{B}$ be the relation of betweenness.

Let $=$ be the relation of equality.


 * $\forall a,b: \mathsf{B}aba \implies a = b$

Intuition
If between a point and itself lies another point, we're dealing with exactly one point.