Limit Point Darts
Definition: A point is a limit point L in a topological space, if any neighborhood of that point contains another point distinct from L. We will visualize this with darts.
Throw the darts (by swiping your screen) to mark a sequence of points, and to help us prove the target center is a limit point. [Instead of a general or infinite set, we will let you win after finding 10 points.]