1
Q
Path Lifting Lemma
A
if σ is a path starting at 1 in S1, then there exists unique σ’ starting at 0 in R st diagram commutes (p from R to S1)
2
Q
homotopy lifting lemma
A
if τ is another path starting at 1 in S1 and σ - τ via homotopy F then σ’ - τ’ via a unique homotopy F’
3
Q
lebesgue covering lemma
A
