Section 54: Problem 1 Solution
Working problems is a crucial part of learning mathematics. No one can learn topology merely by poring over the definitions, theorems, and examples that are worked out in the text. One must work part of it out for oneself. To provide that opportunity is the purpose of the exercises.
James R. Munkres
What goes wrong with the “path-lifting lemma” (Lemma 54.1) for the local homeomorphism of Example 2 of §53?
In the construction of the lifting at each step it is assumed that the new segment is homeomorphic to some neighborhood of the last point where the path is already constructed, so that the unique path in that neighborhood can be uniquely lifted up, however, if there is no such neighborhood for a point, then the construction may be not possible. For that particular example if we take
and the path
, then however we split the unit interval there must be a subinterval
, and as it is easy to see the lifting
of
up to this point should be
, so that
should be a connected interval of the form
, containing
, which is not possible.