deletions | additions       diff --git a/laws summation.tex b/laws summation.tex  index 57d336f..bfb1895 100644  --- a/laws summation.tex  +++ b/laws summation.tex 
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These summation laws/formulas are used.  They are very common and thus we won't prove any of them.  Most of them can be found \href{http://en.wikipedia.org/wiki/Summation}{here} \href{http://en.wikipedia.org/wiki/Summation}{here}.  \begin{enumerate}  \item $\displaystyle\sum_{n=s}^t C\cdot f(n) = C\cdot \sum_{n=s}^t f(n)$