"A squirrel is clinging tightly to the trunk of a large tree. On the
other side of the tree, close up against the trunk is a hunter.
Every time the hunter moves to his left, the squirrel moves
quickly to its left too, scurrying further round the trunk,
hanging on with its claws. The hunter keeps trying to find the
squirrel, but it manages to keep just out of his sight. This goes
on for hours, and the hunter never gets a glimpse of the squirrel.
Would it be true to say that the hunter is circling the squirrel?
Think about it. Does the hunter actually circle his prey?"