deletions | additions       diff --git a/untitled.tex b/untitled.tex  index 9beb08e..7d2963b 100644  --- a/untitled.tex  +++ b/untitled.tex 
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\frac{z}{z-\frac12} - \frac{z}{z+\frac12} &=   \left( \frac{z}{z-\frac12} - \frac{z-\frac12}{z-\frac12}\right) -   \left( \frac{z}{z-\frac12}- \frac{z+\frac12}{z+\frac12} \right)  \\  &=  \frac12 \frac{1}{z-\frac12} + \frac12 \frac{1}{z+\frac12}  \; .