Consider the 2D region:

|...|1  1  1  1  1|1  1  1  1 -1|1  1  1 -1 -1|1  1 -1 -1 -1|1 -1 -1 -1 -1 ...+---------

Ie, we have a "diamond" of 1s:

|...|* * * * *|* * *|* * *|* *|*+---------

• If we add up each of the x axes first, we see that it adds up to -infinity, so then when we add up the sums, we get -infinity.
• On the other hand, each of the y axes has infinitey many *s (1s) if we start adding from the bottom, so they will "wash over" the finite number of blank spaces (-1s), meaning that each y axis