Surface with boundary
= Surface with boundary
{wiki=Manifold_with_boundary}
A surface with boundary is locally homeomorphic either to the plane or to the closed upper half-plane. Points of the second kind form its one-dimensional boundary.
= Surface with boundary
{wiki=Manifold_with_boundary}
A surface with boundary is locally homeomorphic either to the plane or to the closed upper half-plane. Points of the second kind form its one-dimensional boundary.