Example 42.68.21. Let $R = k$ be a field. Let $M = k^{\oplus a} \oplus k^{\oplus b}$ be $l = a + b$ dimensional. Let $\varphi $ and $\psi $ be the following diagonal matrices

with $u_ i, v_ j \in k^*$. In this case we have

This can be seen by a direct computation or by computing in case $l = 1$ and using the additivity of Lemma 42.68.18.

## Comments (0)