classification of covering spaces
Let X be a connected, locally path connected and semilocally simply
connected space. Assume furthermore that X has a basepoint *.
A covering p:E→X is called based if E is endowed with a
basepoint e and p(e)=*. Two based coverings pi:Ei→X, i=1,2 are called
equivalent if there is a basepoint preserving equivalence T:E1→E2 that
covers the identity
, i.e. T is a homeomorphism and the following diagram
commutes