deletions | additions       diff --git a/Curious Mappings.tex b/Curious Mappings.tex  index f54cba7..17c371c 100644  --- a/Curious Mappings.tex  +++ b/Curious Mappings.tex 
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Try \begin{equation}  F_{ij}= F_{ij}^S=  \sum _{k=j-i}^{j+i} S_k \end{equation}