(Lifting lemma): Let M be a Hausdorff space and letbe the projection map. Let
be a continuous map. Then there is a continuous map
such that
.
Proof of Lemma 5.1. We use induction on n. The case n=1 is trivial, so assume n > 1. By Sublemma 5.1, it suffices to find a lift on each connected component I of. By Sublemma 5.5 it suffices to show that any
has a neighborhood on which there is a lift.
Suppose
(
) are the distinct elements of the multiset
, occurring with multiplicities
respectively. Since M is Hausdorff, there exist pairwise disjoint neighborhoods
of
. Let N be a closed interval neighborhood of
such that
implies
. Then on N, we can lift f to a path
in
since the projection
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restricts to a homeomorphism on the projections of
. By the inductive hypothesis applied to each of the k coordinates of
, we can lift
to a path in
as desired.