deletions | additions       diff --git a/introduction.tex b/introduction.tex  index cf00c34..80b6506 100644  --- a/introduction.tex  +++ b/introduction.tex 
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\par  A segunda derivada espacial do potencial gravitacional   \begin{equation}   g_{\alpha \beta}(\bf r) = \frac{\partial^2 g {g}  }{\partial \alpha \partial \beta} \end{equation}  \par   A segunda derivada espacial do potencial gravitacional