General linear group:GL(2,Z9)

Definition
This group can be defined in the following equivalent ways:


 * 1) It is the group $$GL(2,\mathbb{Z}_9)$$ or $$GL(2,\mathbb{Z}/9\mathbb{Z})$$, i.e., the defining ingredient::general linear group of degree two over the ring of integers modulo $$9$$.
 * 2) It is the group $$GL(2,\mathbb{F}_3[t]/(t^2))$$, i.e., the general linear group of degree two over the ring $$\mathbb{F}_3[t]/(t^2)$$.

Note that although the rings in question are different, the corresponding general linear groups are isomorphic.