It's ambiguous. The end condition could be a pixel spawning with overlap on a ball because there's nowhere else to go. What will happen when there's no room lef

It's ambiguous. The end condition could be a pixel spawning with overlap on a ball because there's nowhere else to go. What will happen when there's no room left to add one more pixel, and it tries to add one more pixel? Will it place it with the collision boundaries on the wrong sides? Will it crash with a null value error because there's no good spot to place it? Can't know without understanding the code. But there are many possible end conditions. They're asking if one can prove that you never reach any situation where an end condition (intended or not) could ever exist. Imagine black has a long horizontal 1 pixel tunnel, but it's zigzagging down hitting every side pixel rapidly, while white has a long white tunnel and it's bouncing perfectly horizontally, taking a long time to hit each end. As the ends close in on white, is there some perfectly aligned timespan where black can hit a pixel while white doesn't have a full pixel of open space on either side? It would be interesting if someone can articulate logically why or why not that would ever happen.