# References and Originality

This repository is an original MoonBit implementation. It is not copied from or mechanically translated from another decision-tree library.

The implementation uses standard definitions described by these public references:

- Breiman, Friedman, Olshen, and Stone, *Classification and Regression Trees*, 1984.
- scikit-learn documentation, "Decision Trees" and model evaluation definitions: <https://scikit-learn.org/stable/modules/tree.html>
- Wikipedia, "Decision tree learning": <https://en.wikipedia.org/wiki/Decision_tree_learning>

These references informed terminology and formulas such as Gini impurity, entropy, variance reduction, and cost-complexity pruning. The source code, API design, deterministic tie rules, validation layer, exporters, and tests in this repository were written for MoonBit. No third-party source code is included, so no upstream software license is inherited.