xxx: Lord, here are: 1. bilinear forms? Those who have at least one singular number. Those who have a jordan shape? Those whose norm is consistent with the norms of any pair of linear spaces.
YYY: I also want to make me such a pearl!
zzz: Divide an imaginary unit by zero. You will see the trigonal space in the form of a broken oscillograph.
XXX: And now I want to be so pissed.