deletions | additions       diff --git a/introduction.tex b/introduction.tex  index c06f539..2fa3580 100644  --- a/introduction.tex  +++ b/introduction.tex 
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com condi\c{c}\~oes de fronteiras de Dirichlet a expressão:  \begin{equation}  h(x,y,z) =   \sum^{\infty}_{n=0} \sum^{\infty}_{m=0} \{ exp (-2pi) -2 \pi (k_x^2 +k_y^2)^1/2  \} A_{n}  \end{equation}