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I want to show that Aut$K_4\cong S_3$, where $K_4$ is the Klein's 4-group. I have shown that there exist 6 automorphsms from $K_4$ to $K_4$. But how to show that Aut$K_4$ is nonabelian?

Anupam
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1 Answers1

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There are group $3$ elements of order $2$ in $\bf{V}$ has so every $\phi\in\text{Aut}(\bf{V})$ permutes the $3$ involutions. By taking $G=\mathbf{V}-\{1\}$ which is of order $3$ then $$\phi\mapsto \phi|_{G}$$ is a homomorphism from $\text{Aut}(\bf{V})$ to $S_G$. Show that this map is an isomorphism.

Mikasa
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