Proof. [02CV]
Original official author HTML, exact retained edition. Historical TeX conversion verdicts remain unchanged. Cited-edition alignment and mathematical self-containment are not assessed.
Complete original source context · Original author HTML
Proof.
Since the problem is local, we may assume for all that the above map exists and is as small as we like. For simplicity we denote , and . Now we first define on . Inductively suppose is defined on satisfying on for some rotation , then we apply Lemma 5.9 to the two maps and with and , and obtain a map defined on satisfying (2). Then we define to be on . By Lemma 5.9 we see that all the ’s match together to a map from to , and we can modify slightly near so that the image is exactly . It is easy to see that , and extends to a continuous metric tensor over . ∎