playing with md and superset typography

documentation/design/05-implementation.md

@@ -19,9 +19,10 @@ the network for a longer time, i.e., multiple minutes or even longer.
 
 ### Topology Inventories
 
-Every network has one given physical topology and on top of this at least one
-logical topology. There may be multiple logical topologies on top logical
-topologies, i.e., a recursion.
+Every network has one given physical topology (G<sub>physical</sub> ) and on
+top of this at least one logical topology (G<sub>logical1</sub>). There may be
+multiple logical topologies (G<sub>n+1</sub>) on top logical topologies
+(G<sub>n</sub>), i.e., a recursion.
 
 A topology consists out of interfaces, which are attached to their respective
 network elements, and links between these interfaces.
@@ -30,7 +31,7 @@ Mathematically, such a topology can be described as a directed graph, whereas
 the interfaces of the network elements are the nodes and the links are
 the edges.
 
-G <sub>physical</sub> ist a superset of G <sub>logical1</sub>. 
+G<sub>physical</sub> ist a superset of G<sub>logical1</sub>.
 
 
 ### Potential other Inventories