https://cis.temple.edu/~wu/research/publications/Publication_files/ICDE2024_Xu.pdf
Similar to Lemma 1, we can also prove that the mapping satisfies the assumptions (H1-H5) in [37]. Next, given this contraction mapping, there exists a unique fixed-point based on the fixed-point theorem, i.e., the fixed point can be found by initializing the iterations with an arbitrary point.