Quantum Structural Theory of Harmony (QSTH M. 2) — Source Review of the Older Horizon Set Line: Alpha-I-Dim, Sₑff, R-Signature, and the Galois Ledger

Abstract This publication presents QSTH M. 2 as a source review of the older Horizon Set line within the M-series of the Quantum Structural Theory of Harmony. It follows the public opening of QSTH 8. M. x, the technical alpha closure of QSTH M. 0, and the unit-scale audit of QSTH M. 1. It does not claim empirical confirmation of an M-independent horizon. Its purpose is to reconstruct the genealogy of the M. x equation layer and to distinguish source memory, algebraic identities, candidate physical interpretations, support bridges, and future formalization paths. The central result of M. 2 is that M. x is not an isolated new equation. It is a return to the older Horizon Set line with the Alpha-I-Dim handle now made explicit. The original Horizon Set contained four visible pillars: the M-independent equation, its Planckian form, the R-Signature, and Sₑff. After M. 1, Alpha-I-Dim appears as a latent fifth handle hidden in the Planckian form LambdalP², because the Planck-Cosmic Coupling Identity gives LambdalP² = 3*alphaI-Dim². The publication reconstructs the older M-independent skeleton and its alpha-form, clarifies the role of R-Signature as a Planck-normalized thermal-length regime indicator, and distinguishes two Sₑff perspectives: the older entropy-cost convention and the modern readability-balance convention. After the M. 5/Galois update, SₑffH is no longer treated as a free entropic correction, but as a CAND-computable scaffold with a legitimate microstate path through epsilonR, the ratio Omegacoh, R / Omegaᵣed, R, and the Galois orbital sieve Pi, G, Orb, S/T/J. M. 2 also introduces the Galois Ledger as an older formal stone newly recognized inside the M. x branch, and records Feynman ledger language and Hilbert / Diagram-Hilbert as support and future formalization bridges. The document concludes with a CORE / CAND / SUPPORT / FUTURE status audit, failure modes, and a skeptical contract requiring that older sources function as audit memory rather than as proof. Description This record contains the English final version of QSTH M. 2 — Source Review of the Older Horizon Set Line, a source-review publication in the QSTH M-series. The document follows QSTH 8. M. x — Horizon Ledger of the Settled Structure, QSTH M. 0 — M-Independent Horizon: Alpha Closure of the Horizon Ledger, and QSTH M. 1 — Unit Hygiene and Alpha-I-Dim Audit: The Planck-Cosmic Coupling Identity. The publication examines the older Horizon Set source line and reconstructs the genealogy of the M-independent horizon framework. It shows how the M-independent equation, the Planckian form, R-Signature, Sₑff, Alpha-I-Dim, CORE Trio, Galois Ledger, Feynman ledger language, and Hilbert / Diagram-Hilbert support lines contribute to the current M. x architecture. The document includes: an Epistemic Note / Methodological Brake, the transition from QSTH 8. M. x through M. 0 and M. 1 to M. 2, a source review map, the genealogy of the older Horizon Set line, reconstruction of the M-independent horizon equation, the alpha-form of horizon closure, R-Signature as a thermal-length regime indicator, Sₑff as the horizon ledger account, the M. 5/Galois update of SₑffH, Alpha-I-Dim as the latent fifth Horizon Set handle, CORE Trio as a support structure for ledger, geometry, interface, and scale, the Galois Ledger as an invariance and microstate-sieve layer, Feynman / Hilbert / Diagram-Hilbert as support and future formalization bridges, a CORE / CAND / SUPPORT / FUTURE status audit, an equation capsule, failure modes, a skeptical contract, and a bridge toward QSTH M. 3. This publication should be read as a theoretical and methodological source review. It does not claim empirical confirmation of QSTH or of an M-independent horizon. Its purpose is to clarify the origin, status, and audit role of the older Horizon Set components before the M-series proceeds into the calibration atlas of horizon classes. Related work note This publication follows QSTH 8. M. x — Horizon Ledger of the Settled Structure, QSTH M. 0 — M-Independent Horizon: Alpha Closure of the Horizon Ledger, and QSTH M. 1 — Unit Hygiene and Alpha-I-Dim Audit: The Planck-Cosmic Coupling Identity. It provides the source-review layer of the M-series and prepares the transition toward QSTH M. 3 — Calibration Atlas of Horizon Classes. Plain-language summary This publication asks where the M. x horizon equations came from. It shows that the M-independent horizon framework did not appear as an isolated new idea, but grew out of the older Horizon Set line. Alpha-I-Dim is identified as a latent fifth handle hidden in the Planckian form of the older equations, while the Galois Ledger explains how the horizon account should distinguish ledger-visible invariants from microstate rewrites. Final Zenodo caveat This document is a theoretical and methodological source-review publication. It does not claim that QSTH is empirically confirmed, nor does it present the M-independent horizon as an established physical object. Older QSTH source materials are treated as audit memory and genealogy, not as proof. The purpose of this publication is to define the source lineage, equation status, failure modes, and future formalization bridges of the M-series. Suggested citation Stepanik, R. (2026). QSTH M. 2 — Source Review of the Older Horizon Set Line. Quantum Structural Theory of Harmony, EN v1. 0 Final / 8. M. x, M. 0, M. 1 & Galois Alignment. Zenodo. Subjects / categories Physics — Theoretical PhysicsMathematical PhysicsQuantum PhysicsCosmology and Nongalactic AstrophysicsInformation Theory Copyright Copyright (C) 2026 Rostislav Stepanik