(1) Plain English. The declaration c_rs_eq_one asserts that the RS-native speed of light equals exactly one voxel per tick.
(2) Why it matters in Recognition Science. In the framework, c is not an empirical input but the structural ratio ℓ₀/τ₀ where both fundamental length and time are defined as unit. This makes causal propagation a unit coherence bound rather than a fitted constant; all other constants (ℏ, G, α) are then expressed algebraically in φ.
(3) How to read the formal statement. The Lean statement is theorem c_rs_eq_one : c_rs = 1 := by unfold c_rs ℓ₀ τ₀ norm_num. It first defines c_rs : ℝ := ℓ₀ / τ₀, then unfolds the definitions (both ℓ₀ and τ₀ equal 1) and normalizes to obtain equality. The proof is a direct computation with no external axioms.
(4) Visible dependencies or certificates. The theorem lives in IndisputableMonolith.Foundation.ConstantDerivations and depends only on the local definitions c_rs, ℓ₀, and τ₀. It is referenced verbatim as ConstantDerivations.c_rs_eq_one inside the master certificate reality_from_one_distinction and the propositional form reality_forced_by_any_distinction. Related local results include c_pos and all_constants_from_phi.
(5) What this declaration does not prove. It does not derive why ℓ₀ = τ₀ = 1 from the forcing chain (that occurs upstream in PhiForcing and DimensionForcing), does not address SI calibration or empirical measurement (handled in SingleAnchor), and does not prove the full physical emergence of spacetime or the light cone (those appear in SpacetimeEmergence and RealityFromDistinction).