Ring $R_{ 154 }$

Description:

Let $V_1=\mathbb Z[i]_{(2-i)}$ and $V_2=\mathbb Z[i]_{(2+i)}$ and $V=V_1\cap V_2$. The ring is $\begin{bmatrix}\bar\alpha && x \\ 0 && \alpha\end{bmatrix}$ where $\alpha\in V$ and $x\in \mathbb Q[i]/V_1$. It is isomorphic to the endomorphism ring of module 12.

Keywords subring trivial extension