deletions | additions       diff --git a/Here_I_refers_to_I__.tex b/Here_I_refers_to_I__.tex  index 6161be8..cb0de15 100644  --- a/Here_I_refers_to_I__.tex  +++ b/Here_I_refers_to_I__.tex 
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Here, $I$ refers to $I(\vec{r})$Note $I(\vec{r},v)$ and $I'$ refers to $I(\vec{r}+\delta \vec{r}, v+\delta v)$. Note  that the average of all the mixed terms is treated as being close to zero, since we're expecting