The normal to a 4 dimensional plane has 4 components and is defined by the cross product of 3 nonparallel vectors in the plane, or by the cross product
of 3 nonparallel vectors defined by 4 noncollinear points on the plane.
So far I have read no evidence that Carolyn is dead. Maybe she just stopped bugging me as much as usual. Maybe she is alive and well and doing fine.
Maybe I just stopped giving her free room for rent in my mind. What is my "mind" anyway? Do I actually still have one?