Update README.md

README.md

@@ -129,7 +129,7 @@ This is a short outline of the algorithm. Two circles $A$ and $B$ define the cir
 $A = \lbrace p \in \mathbb{R}^3 \mid p \cdot a = \cos \alpha \land |p| = 1 \rbrace$ <br/>
 $B = \lbrace p \in \mathbb{R}^3 \mid p \cdot b = \cos \beta \land |p| = 1 \rbrace$ 
 
-(From now on we assume all coordinates/vectors are located on the unity sphere, i.e. $|p| = 1$, i.e. the Earth has "radius = 1")
+(From now on we assume all coordinates/vectors are located on the unity sphere, i.e. $\lbrace p \in \mathbb{R}^3 \mid |p| = 1 \rbrace$, i.e. the Earth is threedimensional and its surface has "radius = 1")
 
 We aim for finding the intersections $p_1$ and $p_2$ for the circles $A$ and $B$ and the point $q$ being the midpoint between $p_1$ and $p_2$.