R12 Suffix-Partition Selection for Half-Collinear Single-Minus Tree Amplitudes

This Zenodo record contains an independent, AI assisted response note to the preprint Single minus gluon tree amplitudes are nonzero (arXiv:2602.12176). The original work drew attention both for its physics result (non vanishing single minus tree amplitudes in a half collinear regime) and for an explicit AI assisted component in the derivation. Scope and intentThe goal here is not to claim priority over the underlying discovery. The goal is to demonstrate a reproducible, audit ready workflow for rapid technical follow up on a fresh theoretical result, using multiple AI systems under strict human control, with convention locks and integrity hashes. What this record provides Technical noteA short note focused on the two incoming sign region R12, defined by omega 1 less than 0, omega 2 less than 0, and omega a greater than 0 for a at least 3, for the cyclic ordering A_{3,4,...,n,1,2}. Structural selection rule (suffix partition selection)By invoking the all positive block vanishing mechanism from the R1 analysis in the original paper, we show that in R12 any ordered partition term containing an all positive consecutive block of length at least 2 must vanish. Therefore, every block before the final block (the unique block containing leg 1 in the prefix word) must be a singleton. This reduces the candidate partition shapes from exponential growth to a linear size suffix family. Reproducible numerical witnesses up to n equals 9For each n equals 5 to 9 we verify that no contributing partition lies outside the suffix family (Extras equals 0). For n equals 9 we provide at least one explicit term witness for each of the six nontrivial suffix shapes (n minus 3 equals 6 for n equals 9), including random seeds and convention locks. Two boundary shapes vanish identically by convention (the single block partition where cPT equals 0, and the length 2 suffix where Abar(n,1) equals 0), leaving n minus 3 nontrivial shapes. Artifacts and reproducibilityThis upload includes: The PDF note A RefereePack zip bundle containing JSON outputs, witness seeds, convention locks, and SHA256 hashes for integrity checks AI assisted workflow (human curated)The following AI tools were used during drafting and code prototyping: OpenAI ChatGPT (GPT 5.2)Anthropic Claude (Sonnet 4.6)Google NotebookLM All prompts were curated by the author. Outputs were checked for internal consistency and reproducibility against the stated definitions and convention locks. The author takes responsibility for the organization, provenance, and reproducibility of the materials, while inviting expert review of the physics claims using the provided RefereePack. Keywordshalf collinear limit; Yang Mills; tree amplitudes; single minus; ordered partitions; recursion collapse; reproducible research; AI assisted mathematics Related workarXiv:2602.12176 (DOI 10.48550/arXiv.2602.12176)