diff --git a/submission_thesis/CH1_introduction/copy.tex b/submission_thesis/CH1_introduction/copy.tex
index 7132d32..60c8f59 100644
--- a/submission_thesis/CH1_introduction/copy.tex
+++ b/submission_thesis/CH1_introduction/copy.tex
@@ -14,7 +14,7 @@ Blanket measures, RAM ROM checks, EMC, electrical and environmental stress testi
 \subsection{Practical limitations of testing for certification vs. rigorous approach}
 
 State explosion problem considering a failure mode of a given component against
-all other components in the system.
+all other components in the system i.e. an exponential (2^N) order of processing resource rather than a ploynomial i.e. N^2.
 
 Impossible to perform double simultaneous failure analysis (as demanded by EN298~\cite{en298}).