# 6.2 – Aut | The notion of level

The chamber structure over $\nps$ can be layered into levels.

The notion of level for chambers is defined iteratively, as follows:

We pick an initial chamber, denoted by $D_{0}$
and defined as the only level $0$ chamber.

A chamber adjacent to a level $l-1$ chamber
but not adjacent to a level $l-2$ chamber is said to be of level $l.$