diff --git a/opamp_circuits_C_GARRETT/opamps.tex b/opamp_circuits_C_GARRETT/opamps.tex
index 13ece3e..2369af3 100644
--- a/opamp_circuits_C_GARRETT/opamps.tex
+++ b/opamp_circuits_C_GARRETT/opamps.tex
@@ -813,7 +813,7 @@ This can be simplified if we can determine the total number of failure modes in
 equation~\ref{eqn:rd} becomes $$ RD(fg) = fT.(|fg|-1).$$
 
 \pagebreak[4]
-\subsection{Reasoning Distance Examples}(c-1)
+\subsection{Reasoning Distance Examples}
 
 The potential divider discussed in section~\ref{potdivfmmd} has a four failure modes and two components and therefore has an $RD$ of 4.
 $$RD(potdiv) = \sum_{n=1}^{2} |2|.(|1|) = 4 $$
@@ -910,6 +910,26 @@ We can now use  equation~\ref{eqn:anscen} and \ref{eqn:fmea_state_exp22} to comp
 the two approaches, for the work required to perform rigorous checking.
 
 
+For instance, having four levels 
+of FMMD analysis, with these fixed numbers,
+%(in addition to the top zeroth level)
+will require 81 base level components.
+
+$$
+%\begin{equation}
+  \label{eqn:fmea_state_exp22}
+  3^4.(3^4-1).3 = 81.(81-1).3 = 19440 % \\
+  %(N^2 - N).f 
+%\end{equation}
+$$
+
+$$
+%\begin{equation}
+ % \label{eqn:anscen}
+  \sum_{n=0}^{3} {3}^{n}.3.3.(2) = 720
+%\end{equation}
+$$
+
 \subsection{Exponential squared to Exponential}
 
 can I say that ?