From ad1767f90cdcaea6c38f868c6c1c49a00cd3c4f6 Mon Sep 17 00:00:00 2001
From: Robin Clark <r.clark@energytechnologycontrol.com>
Date: Mon, 10 Jan 2011 16:46:14 +0000
Subject: [PATCH] .

---
 .../component_failure_modes_definition.tex               | 9 +++++----
 survey/survey.tex                                        | 4 ++--
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/component_failure_modes_definition/component_failure_modes_definition.tex b/component_failure_modes_definition/component_failure_modes_definition.tex
index f7c3013..506157d 100644
--- a/component_failure_modes_definition/component_failure_modes_definition.tex
+++ b/component_failure_modes_definition/component_failure_modes_definition.tex
@@ -761,7 +761,7 @@ We can model this using an Euler diagram representation of
 an example component with three failure modes $\{ B_1, B_2, B_3, OK \}$ see figure \ref{fig:combco}.
 
 For the purpose of example let us consider $\{ B_2, B_3 \}$
-to be intrinsically mutually exclusive, by $B_1$ to be independent.
+to be intrinsically mutually exclusive, but $B_1$ to be independent.
 This means the we have the possibility of two new combinations
 $ B_1 \cap B_2$ and $ B_1 \cap B_3$.
 We can represent these 
@@ -794,17 +794,18 @@ Thus for $P(B_1 \cap B_2) = P(B_1)P(B_2)$ and  $P(B_1 \cap B_3) = P(B_1)P(B_3)$.
 \end{figure}
 
 
-We can now consider the shaded areas as new failure modes of the component.
+We can now consider the shaded areas as new failure modes of the component (see figure \ref{fig:combco3}).
 Because of the combinations, the probabilities for the failure modes
 $B_1, B_2$ and $B_3$ will now reduce.
-We can use the prime character ($/prime$), to represent the altered value for a failure mode, i.e.
+We can use the prime character ($\; \prime \;$), to represent the altered value for a failure mode, i.e.
 $B_1^\prime$ represents the altered value for $B_1$.
 Thus
 $$ P(B_1^\prime) = B_1 - P(B_1 \cap B_2) - P(B_1 \cap B_3)\; , $$
 $$ P(B_2^\prime) = B_2 - P(B_1 \cap B_2) \; and $$ 
 $$ P(B_3^\prime) = B_3 - P(B_1 \cap B_3) \; . $$
 
-
+We now have two new component failure mode $B_4$ and $B_5$, shown in figure \ref{fig:combco3}.
+We can express their probabilities as $P(B_4) = P(B_1 \cap B_3)$ and $P(B_5) = P(B_1 \cap B_2)$.
 
 
 %%-
diff --git a/survey/survey.tex b/survey/survey.tex
index 4dcc57e..4d06f19 100644
--- a/survey/survey.tex
+++ b/survey/survey.tex
@@ -4,12 +4,12 @@
 \ifthenelse {\boolean{paper}}
 {
 \begin{abstract}
-A survey of Static Failure Mode analysis Methodologies applicable to saefty critical systems.
+A survey of Static Failure Mode analysis Methodologies applicable to safety critical systems.
 \end{abstract}
 }
 {
 \section{Overvew}
-A survey of Static Failure Mode analysis Methodologies applicable to saefty critical systems.
+A survey of Static Failure Mode analysis Methodologies applicable to safety critical systems.
 }
 
 There are four methodologies in common use for failure mode modelling.