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. The 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 omega1 < 0, omega2 < 0, and omega_a > 0 for a >= 3, for the cyclic ordering A3,4,...,n,1,2. Structural selection rule (suffix partition selection)By importing 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 = 9For each n = 5,...,9 we verify that no contributing partition lies outside the suffix family (Extras = 0). For n = 9 we provide at least one explicit witness for each of the six nontrivial suffix shapes (n minus 3), including random seeds and convention locks. Artifacts and reproducibility This 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 validated against the definitions and internal consistency checks. The author takes full responsibility for all claims, computations, and interpretations. Keywords half collinear limit; Yang Mills; tree amplitudes; single minus; ordered partitions; recursion collapse; reproducible research; AI assisted mathematics. Related work arXiv:2602.12176 (DOI 10.48550/arXiv.2602.12176)