Topology abstracts geometry by focusing on openness and closeness.
Open Set: Every point in the set has a neighborhood completely contained within the
set.
Closed Set: Contains all its boundary points.
Interact with the sets below to test their topological properties by probing with an "open ball"
($B_\epsilon$).
Hover over the canvas to probe the set.
Select a Set Topology:
An Interior Point is a point where you can find some radius string $\epsilon > 0$
such that the entire ball stays inside the set.
A Boundary Point is a point where any ball you draw contains points both inside
and outside the set.