Suppose that 
are arcwise-connected and locally
arcwise-connected topological spaces. Then
is said to be a covering space
of 
if 
is a surjective continuous map with every 
having an open neighborhood 
such that every connected
component of 
is mapped homeomorphically onto 
by 
.
Covering Space
See also
Covering Map, Deck Transformation, Fundamental Group, Universal CoverExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Covering Space." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CoveringSpace.html