Authors: Se Kyun Kwon, Hye Neung Kwon
The XOR problem has long been cited as proof that neural networks require nonlinear activation functions to learn nonlinearly separable decision boundaries. We argue that this interpretation is reversed. XOR is not evidence that nonlinearity is required; it is evidence that learning is fundamentally topological. We demonstrate that XOR can be solved by a purely piecewise-linear model, provided that the input space is partitioned into local patches and those patches are reconnected by a learned transition rule.No nonlinear activation is applied to the value branches. The softmax gate acts solely as a transition rule defining the topological partition of the input domain. In this view, learning is the act of cutting and gluing regions of input space—a process that induces a nontrivial holonomy similar to a monopole-like singularity. Because topological quantities are invariant under continuous deformation, all solutions of XOR—whether through ReLU, sigmoid, tanh, high-dimensional lifting, or discrete gating—are merely different coordinate representations of the same topological object.Continuity, differentiability, and analytic activation functions are not the essence of learning; the topology of how input regions are divided and re-attached is.
Comments: 5 Pages.
Download: PDF
[v1] 2025-11-17 02:06:06
Unique-IP document downloads: 161 times
Vixra.org is a pre-print repository rather than a journal. Articles hosted may not yet have been verified by peer-review and should be treated as preliminary. In particular, anything that appears to include financial or legal advice or proposed medical treatments should be treated with due caution. Vixra.org will not be responsible for any consequences of actions that result from any form of use of any documents on this website.
Add your own feedback and questions here:
You are equally welcome to be positive or negative about any paper but please be polite. If you are being critical you must mention at least one specific error, otherwise your comment will be deleted as unhelpful.