cert
plain-language theorem explainer
Packages three elementary properties of the module-9 domain cost (vanishes on the diagonal, nonnegative for positive arguments, positive canonical threshold) into one certificate record. Cited by anyone treating Physics Module 9 as a discharged structural unit. Construction is a pure structure assembly from three sibling lemmas; no new mathematics.
Claim. There is a certificate record asserting: (i) the domain cost of any nonzero real against itself is zero; (ii) for positive mass parameters $m,e>0$ the domain cost is nonnegative; (iii) the canonical threshold is strictly positive.
background
Physics RS Module 9 targets the proton-electron mass ratio in the Recognition framework. The module notes that $\varphi^{12}\approx 321.9$, leaving a residual factor $\sim 5.7$ relative to the observed $\approx 1836$, so the present content is structural rather than a finished mass prediction.
The certificate type bundles three properties of a local domain cost (a real-valued cost on pairs of positive reals, built from the global $J$-cost $J(x)=(x+x^{-1})/2-1$). Upstream, nonnegativity of recognition-event cost is already known: any recognition event has $0\le e.\mathrm{cost}$ via $J$-cost nonnegativity. The siblings domainCost_at_eq, domainCost_nonneg, and canonicalThreshold_pos specialize that picture to the module-9 cost and threshold.
Status of the module is STRUCTURAL THEOREM (zero sorry, zero axiom).
proof idea
Pure structure constructor. The three fields of the certificate are filled by the already-proved sibling facts: diagonal vanishing of the domain cost, nonnegativity of the domain cost on positive arguments, and positivity of the canonical threshold. No tactics, no new lemmas.
why it matters
Gives a single named inhabitant of the Module-9 certificate type so downstream code can treat the three cost/threshold axioms as one discharged package. The module itself is the structural shell around the proton-electron mass-ratio discussion ($\varphi^{12}\approx 321.9$ versus observed $\approx 1836$). It does not yet close the residual gap factor; it only certifies that the local cost geometry is well-behaved (zero on equals, nonnegative, positive threshold), consistent with the global $J$-cost minimum at identity and the forcing-chain uniqueness of $J$. No downstream users are recorded in the graph yet; the companion cert_inhabited is the natural next consumer.
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