Solution (source code)

= Solution

In characteristic three with $n=5$, a constant <vector> $(c,c,c,c,c)$ belongs to the augmentation <submodule> only if $5c=0$, which forces $c=0$. Thus $S^{(4,1)}$ has no trivial <submodule>. Part (b) proves that it is \b[simple], of dimension four, and therefore equals $D^{(4,1)}$.