Explanation of the theorem match_rsbridge_rung_neutrinos
(1) In plain English, the declaration states that the rung values produced by compute_rung for the three neutrino generations (nu1, nu2, nu3) are identical to the legacy values returned by RSBridge.rung.
(2) In Recognition Science this matters because it verifies that the new rung constructor preserves the prior mapping for neutrinos (which use baseline 0 due to Z=0 and a distinct +8 generation step for the second generation, per the docstring). This maintains internal consistency of the mass/rung framework across legacy and updated code paths.
(3) The formal statement is the conjunction
compute_rung (.fermion .nu1) = RSBridge.rung .nu1 ∧
compute_rung (.fermion .nu2) = RSBridge.rung .nu2 ∧
compute_rung (.fermion .nu3) = RSBridge.rung .nu3
proved by ⟨rfl, rfl, rfl⟩. In Lean this means each equality holds definitionally by reflexivity; no further rewriting or computation is required.
(4) Visible dependencies in the supplied source are the imported compute_rung (from Motif) and RSBridge.rung (from RSBridge.Anchor), together with the master theorem match_rsbridge_rung that proves the same claim for an arbitrary Fermion by exhaustive case analysis. The neutrino case is one of several specialized matching theorems (e.g., the charged-lepton and quark variants) that feed into the master result.
(5) The declaration does not prove the numerical rung values themselves, the underlying mass-scaling formula, any physical predictions, the SDGT rung variants (which differ for quarks), or empirical comparisons. It only certifies syntactic matching for neutrinos.