deletions | additions       diff --git a/Introduction.tex b/Introduction.tex  index 7b2b69c..d90089b 100644  --- a/Introduction.tex  +++ b/Introduction.tex 
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\section{Introduction}  $\infty \approx \text{http://www.mathmodels.org/problems/probview.php?probnum=20095}$  \text{http://www.gams.com/presentations/birthday_ferris.pdf} $\text{http://www.gams.com/presentations/birthday_ferris.pdf}$