section_path: Generalizations/Topological definition
section_name: Topological definition
paragraph_text: Topological definition
  
  The circle is the one-dimensional hypersphere (the 1-sphere).
  
  In topology, a circle is not limited to the geometric concept, but to all of its homeomorphisms. Two topological circles are equivalent if one can be transformed into the other via a deformation of R upon itself (known as an ambient isotopy).