LaTeX test

Let's see if TeX markup works properly here:

$$f(x) = x * e^{2 pi i \xi x}$$

$$x \in \mathbb{Z}$$

And now some inlined text $f(x) = x * e^{2 pi i \xi x}$ and another one: $g(x) = x * e^{2 pi i \xi x}$

And now let's have a block:

$$f(x) = x * e^{2 pi i \xi x} \newline g(x) = x ^2$$