Equidistant sets and their connectivity properties

If A and B are nonvoid subsets of a metric space (X, d), the set of points x e X for which d(x, A) = d(x, B) is called the equidistant set deternined by A and B. Among other results, it is shown that if A and B are connected and X is Euclidean n-space, then the equidistant set determined by A and B is connected.