# Primary-source audit

Consulted during release preparation on 5 October 2026. The search was targeted, not exhaustive; it does not establish priority.

| Primary source | Role and limitation |
|---|---|
| Vekhter, Chen, Vouga, **MINT** (2025), DOI 10.1111/cgf.70193 | Established volumetric symmetric-frame local integrability and soft orthogonality. No first-local-integrability claim is made here. |
| Nieser, Reitebuch, Polthier, **CubeCover** (2011), DOI 10.1111/j.1467-8659.2011.02014.x | Established field-guided volumetric integration and integer-grid parameterization. |
| Couplet, Chemin, Remacle, **Integrable Frame Fields using Odeco Tensors** (2024), DOI 10.1137/1.9781611978001.5 | Established orthogonal planar-frame integrability using Odeco tensors. |
| Beben, **Topology of Frame Field Design for Hex Meshing**, arXiv:2011.05276 | Established binary-octahedral/topological characterization in its fixed boundary/singularity setting. |
| Lipman, **Bijective Mappings of Meshes with Boundary and the Degree in Mesh Processing** (2014), DOI 10.1137/130939754 | Positive element determinants are insufficient without additional hypotheses. Supplies the conditional boundary-inversion endpoint. |
| Zaslavsky, **Biased Graphs. I. Bias, Balance, and Gains** (1989), DOI 10.1016/0095-8956(89)90063-4 | Gain graphs, cycle balance, and switching are classical. |
| Pietroni et al., **Hex-Mesh Generation and Processing: A Survey**, DOI 10.1145/3554920 | Context for frame-guided parameterization and extraction limitations. |
| European Commission, **AlgoHex final reporting**, grant 853343; updated 14 January 2026 | Explicitly distinguishes local meshability progress from the still-unreached global robustness target. |
| SymPy 1.14.0 official documentation | Recorded exact matrix-normal-form implementation interface; no new algorithmic claim for Smith decomposition. |

Additional adjacent work identified: Zhu et al., **Designing 3D Anisotropic Frame Fields with Odeco Tensors**, arXiv:2505.05639 (2025), and the publisher record for **Surface Quadrilateral Meshing from Integrable Odeco Fields** (2026). These reinforce the need not to claim first anisotropic-frame design or first Odeco integrability. They were not used as unexamined proofs of the release's own results.

The most important further novelty audit concerns rank-one compatibility, differential inclusions, and piecewise-affine orthogonal coordinate maps. The exact interface theorem and quantitative estimate are proved here, but an equivalent earlier result may exist under different terminology.