This is LaTeX code:
[latex]
\sum\limits_{n \geqslant 2} {\frac{1} {{n^2 - 1}}} \ne \frac{1} {2}\sum\limits_{n \geqslant 2} {\frac{1} {{n - 1}}} - \frac{1} {2}\sum\limits_{n \geqslant 2} {\frac{1} {{n + 1}}} = \infty - \infty = ?
[/latex]