feat(dissertation): add formal methods section in background

pub/dissertation/chapters/background.tex

@@ -88,10 +88,21 @@
 % TODO add quick overview of what Formal Methods are
 % Potential resource: https://shemesh.larc.nasa.gov/fm/fm-what.html
 
-\subsection{History}
-
-
-\subsection{Application}
+\begin{itemize}
+  \item Formal methods is a mathematical technique that can be used towards the
+    verification of a system~\cite{nasa:formal}
+  \item This can be used to verify correctness of all the inputs in a system~\cite{nasa:formal}
+  \item Hence, as dealing with safety, it would be beneficial to have
+    the logic of this testing tool verified, to avoid bugs and misleading results
+  \item Airbus also uses formal methods in their avionics systems validation and
+    verification process~\cite{airbus:formal}
+  \item Some examples where Airbus used formal methods was during the development
+    for the Airbus A380, where they used it for proof of absence of stack overflows
+    and analysis of the numerical precision and stability of floating-point operators
+    to name a few~\cite{airbus:formal}
+  \item There are a multitude of specification languages, each of them
+    having their own reasons % TODO don't know if this should be included
+\end{itemize}
 
 
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