When trying to use command blocks to detect when a player leaves a square area by detecting them with circles that have very large radii surrounding the area, I discovered very weird results when the player is farther than 46340 blocks from the centre of the detection radius.

This issue seems to be related to the limitation of the INT data type and how the player's location is calculated because player detection becomes inverted when the square of the radius is grater than 2,147,483,647

I've attached a world save with an example of this issue using a command block with the command:

testfor @a[46340,0,0,1]