M Aschenbrenner, A Fischer - Proceedings of the London …, 2011 - academic.oup.com
Kirszbraun's theorem states that every Lipschitz map S→ ℝ n, where S⊆ ℝ m, has an
extension to a Lipschitz map ℝ m→ ℝ n with the same Lipschitz constant. Its proof relies on …