# Path on $\mathbb{R}^2\setminus \{x_1, x_2\}$

Consider plane $\mathbb{R}^2\setminus \{ x_1, x_2 \}$ without two points, and such closed path on this plane: (points on this picture are deleted points $x_1$ and $x_2$)

Question: how to prove that this path isn't homotopic to zero?

Appendix. As I see, we may fix some point $\alpha\in\mathbb{R}^2\setminus \{ x_1, x_2 \}$ and consider loops $a$ and $b$, which "walk round" point $x_1$ and $x_2$ respectively. Then my path will be homotopic to $$b^{-1}a^{-1}ba$$ as the element of fundamental group ${\pi}_{1} (\mathbb{R}^2\setminus \{ x_1, x_2 \},~\alpha)$.

Thanks a lot!

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This figure is homotopic to the "8" with a hole in each part! – checkmath Mar 14 '12 at 11:06
The fundamental group of your space is equal to free group with two generators. There are no non-trivial relations in this group, so the element you wrote down does not equal the identity. – Thomas Rot Mar 14 '12 at 11:08
@ThomasRot: why give an answer in the comments? – Martin Argerami Mar 14 '12 at 14:55
well, there are some statements that need to be proven there right? – Thomas Rot Mar 14 '12 at 16:16

+1 "nice"   – draks ... Apr 8 '12 at 19:44