• Corpus ID: 38890415

on Serre fibrations

  title={on Serre fibrations},
  author={Stephen A. Mitchell},
Here the solid arrows represent maps that are given, and the problem is to find a map h commuting in the diagram. Usually the map i is an inclusion, and p is some kind of “bundle map” such as a local product. Note the special cases: (i) if i is an inclusion, E = A, and f = 1A, then the extension problem asks whether A is a retract of X; and (ii) if p is surjective, X=B, and g = 1B, the lifting problem asks whether p admits a section. More generally, one can combine the two diagrams into one: A…