deletions | additions       diff --git a/Perspective.tex b/Perspective.tex  index a73dd9b..a3b6b23 100644  --- a/Perspective.tex  +++ b/Perspective.tex 
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\subsection{Presence Detection}  \label{sec:Presence}  \subsubsection{Breakbeam Sensors}  \subsubsection{Reflective Ultrasonic}  \subsubsection{Microswitches}  \subsubsection{Reflective Infrared}  \subsection{Light Sensing}  \label{sec:Photothings}  \subsubsection{Phototransistors}  \subsubsection{Photoresistors}  \subsubsection{Photodiodes}  \subsection{Existing Solutions}  \label{sec:Market_Survey}