Schauder Bases for $c[0, 1]$ Using ReLU, Softplus and Two Sigmoidal Functions

Abstract

We construct four Schauder bases for the space $C[0,1]$, one using ReLU functions, another using Softplus functions, and two more using sigmoidal versions of the ReLU and Softplus functions. This establishes the existence of a basis using these functions for the first time, and improves on the universal approximation property associated with them. We also show an $O(\frac{1}{n})$ approximation bound based on our ReLU basis, and a negative result on constructing multivariate functions using finite combinations of ReLU functions.

Cite

Text

Ganesh et al. "Schauder Bases for $c[0, 1]$ Using ReLU, Softplus and Two Sigmoidal Functions." Transactions on Machine Learning Research, 2025.

Markdown

[Ganesh et al. "Schauder Bases for $c[0, 1]$ Using ReLU, Softplus and Two Sigmoidal Functions." Transactions on Machine Learning Research, 2025.](https://mlanthology.org/tmlr/2025/ganesh2025tmlr-schauder/)

BibTeX

@article{ganesh2025tmlr-schauder,
  title     = {{Schauder Bases for $c[0, 1]$ Using ReLU, Softplus and Two Sigmoidal Functions}},
  author    = {Ganesh, Anand and Bose, Babhrubahan and Rajagopalan, Anand},
  journal   = {Transactions on Machine Learning Research},
  year      = {2025},
  url       = {https://mlanthology.org/tmlr/2025/ganesh2025tmlr-schauder/}
}