Given a map 
from a space 
to a space 
and another map 
from a space 
to a space 
, does there exist a map 
from 
to 
such that 
? If such a map 
exists, then 
is called a lift of 
.
Lifting Problem
See also
Extension Problem, LiftExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Lifting Problem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/LiftingProblem.html