(minor) non-working examples in the manual

[JohnAAbbott]

I have just looked at the (OSCAR) manual entry for hadamard. The example given there triggers an error (because there is no 3x3 Hadamard matrix). While it may sometimes be helpful to give non-working examples, I think it would be good if there were also at least one working example. Comments?

[JohnAAbbott]

We discussed this briefly today, and decided that examples in the manual should not normally provoke errors (outside some rare special cases). It is perhaps not clear how this could be checked automatically.