jcost_ground
plain-language theorem explainer
Ground-state recognition cost vanishes: J(φ⁰) = 0, since φ⁰ = 1 and J(1) = 0. Anyone assembling the forced torsion ladder {0, 11, 17} cites this as the zero base of the J-cost ordering. The proof is a one-line simplification through the zero-exponent law and the unit identity for J.
Claim. The recognition cost of the ground rung is zero: $J(\varphi^{0}) = 0$, where $J(x) = (x + x^{-1})/2 - 1$ and $\varphi$ is the golden-ratio fixed point of the self-similar ladder.
background
In Recognition Science the cost of a positive ratio is $J(x) = (x + x^{-1})/2 - 1$, equivalently $\cosh(\log x) - 1$. It is the unique continuous solution of the Recognition Composition Law forced at T5, and satisfies $J(1) = 0$ with $J(x) > 0$ for $x \neq 1$.
Masses live on the $\varphi$-ladder: a torsion integer $n$ is scored by $J(\varphi^n)$. The module derives the generation torsions ${0, 11, 17}$ as the unique values compatible with the 8-tick Hamiltonian cycle on $Q_3$, projected through RCL additivity of ladder exponents and the CW lower-set constraint on passive couplings.
Variational dynamics already forces the ground-state torsion to zero. The present identity records that this ground rung is costless under $J$, which is the base case of any strict cost ordering along the forced torsion set.
proof idea
One-line simp proof. Rewrite $\varphi^{(0:\mathbb{Z})}$ by the integer power law $z\mapsto z^0 = 1$, then apply the unit identity $J(1) = 0$. No case splits or arithmetic beyond those two rewrites.
why it matters
Supplies the zero conjunct of forced_jcost_ordering, which asserts $J(\varphi^0) = 0 < J(\varphi^{11}) < J(\varphi^{17})$. That ordering is the cost half of the torsion-forcing chain: once RCL makes ladder exponents additive, the 8-tick Gray cycle on $Q_3$ partitions passive cells, and CW attachment forces lower-set profiles, the only admissible generation torsions are ${0, 11, 17}$.
Module step (D) states that any nonzero torsion has positive $J$-cost, so the variational ground state is costless. This lemma is exactly that costless base. It sits downstream of T5 ($J$-uniqueness) and T6 ($\varphi$ as self-similar fixed point), and upstream of the mass-ladder yardstick comparisons that rank the three generations.
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