Let be the Euclidean half plane , with the usual subspace topology. We enrich the topology on by throwing in open sets of the form , that is an open ball of radius around together with its point tangent to (Fig. 1).
The space endowed with the enriched topology is called the Niemytzki plane.
Some miscellaneous properties of the Niemytzki plane are
|Date of creation||2013-03-22 13:36:53|
|Last modified on||2013-03-22 13:36:53|
|Last modified by||PrimeFan (13766)|