The following question refers to http://www.mathhelpforum.com/math-he...-162658-3.html- a post ofBruno J.tochiph588@problem.

I will be glad if someone could explain me why $\displaystyle \sum_{n=0}^\infty \frac1{\alpha^{n-m}+1}=\sum_{n=1}^m \frac1{\alpha^{-n}+1}+F(1)=\sum_{n=1}^m \frac1{\alpha^{-n}+1}+\sum_{n=0}^\infty \frac{1}{\alpha^n+1}$

Thank you!!!