Let $(V,٭)$ be a group where $V=\{a,b,c,d\}$. $(V,٭)$ has the property that every element is an inverse of itself, so $V$ is called the $V$ group or the "Klein 4 group".
I would like to know whether $(V,٭)$ is isomorphic to $(\mathbb{Z}_4,+_4)$. How may I achieve this? Should I try to show that every element of $(\mathbb{Z}_4,+_4)$ is also an inverse of itself? but I think it may not be!