The question is as follows:
Let $S_{\mathbb{N}}$ be the group of all permutation of $\mathbb{N}$. Let $F$ be the subset of $S_{\mathbb{N}}$ consisting of all permutations that fix all but a finite number of points. Let $A\leq F$ be the set of members of $F$ which can be written as a product of an even number of transpositions. Show that $A$ is a simple group.
I would assume that this proof is similar to proving why the alternating group is simple....but am a little stuck on how to go about proving this.