12 of 132 blocks of the round 3 manuscript are new or changed since round 2; 6 of 126 blocks of round 2 no longer appear. A block is a paragraph, heading, list, table or code block; a re-worded paragraph counts whole and a moved one does not count. This compares the two submitted texts and is not the response letter.
New or changed blocks
[under "Thermodynamic consistency and closure limits of radiatively cooled X-point collapse"]
Version 1.1.1; 29 October 2026
[under "5. Normalization and the steady branch"]
Finally, an algebraic steady solution does not establish thermal stability or evolutionary accessibility. Uzdensky and McKinney [3, Section 4.1, pp. 19-21] first derive the evolutionary-accessibility condition $\alpha<1+\beta_T$ in Eq. (57) for $Q_{\rm rad}\propto n^\alpha T^{\beta_T}$. Here $\beta_T$ is a cooling-law exponent, not upstream plasma beta. They subsequently derive thermal stability from the sign of $d(Q_{\rm rad}/Q_{\rm ohm})/dA$, obtaining the same inequality for their closure. Bremsstrahlung $(\alpha,\beta_T)=(2,1/2)$ fails the evolutionary condition, and their separate derivative test identifies its stationary branch as unstable. Allowing length to vary changes the possible branch, but the target supplies no dynamical length-response law or perturbation spectrum proving its stability. We do not transfer the earlier fixed-closure instability criterion unchanged to this new branch, nor infer stability from the mere existence of Eqs. (4.14)-(4.16).
[under "6. Verification, limitations and conclusion"]
The 4,096-state, 150-digit and steady-branch numerical counts are supplementary cross-checks, not load-bearing premises of any conclusion: the displayed identities, inequalities and conditional derivations establish the analytic claims. A separate 150-digit Decimal calculation compares 48- and 96-point scalar quadratures, checks cumulative limits down to $\tau=2^{-320}$, and verifies the coefficient and reduced-equation subleading controls. Another independent calculator checks nine cooling-clock examples, six rational real-power sign cases, 24 parameter cases checking the steady-state identities, and four branch-domain cases. The verifiers do not import the plotting producer. Agreement is numerical and algebraic evidence, not physical accuracy, independent human review or bitwise reproducibility across arbitrary environments.
[under "6. Verification, limitations and conclusion"]
The other 238 integrations consist of 220 ordering trajectories with 11 starts equally spaced from 0.4 to 4 at $\rho_0=1$, and 18 finite-difference trajectories: $P_{0,X}=4$, $\rho_0=1$, $\bar C=0.6$, $x_0=0.25\pm10^{-4}$, $y_0=0,0.4,0.8$, $b=0,1/2,1$, using the changing-rate history. Spatial error is the absolute difference of the centered ODE gradient from the high-precision derivative. Actual environments are CPython 3.12.14/NumPy 2.3.5/Matplotlib 3.11.2 for the plotting producer; CPython 3.13.7/NumPy 2.2.1/SciPy 1.17.1/mpmath 1.3.0 for the direct pressure verifier; and CPython 3.13.7 with the standard library for the two other verifiers. A single combined environment was not tested. NumPy [6] supplies arrays, grids and seeded random controls; SciPy [7] supplies the direct DOP853 solver; Matplotlib [8] renders the three original figures. These citations credit the libraries actually used.
[under "6. Verification, limitations and conclusion"]
For reproducibility, the supplementary outflow sample uses NumPy PCG64 seed 250813081. Four length-4096 arrays are drawn successively: $u_1\sim U[-4,0)$, $u_2\sim U[-2,1)$, $u_3\sim U[-3,2)$ and $u_4\sim U[0,1)$. Set $\xi=e^{u_1}$, $\eta=\xi+e^{u_2}$, $P_{0,X}=e^{u_3}$, $\theta=u_4$, then overwrite $\theta_0=0$. With $\gamma=5/3$, the criterion is that every Eq. (7) acceleration is strictly positive. Two negative-pressure controls fix $(\xi,\eta,P_{0,X})=(1/2,1,1)$ and $\theta=-0.1,-2$: their accelerations have opposite signs.
[under "6. Verification, limitations and conclusion"]
The Decimal checks use 150-digit precision and independently constructed 48- and 96-point Gauss-Legendre rules. For cumulative integrals, $t_c=1$, $\eta=2$, $A=1$, $P_{0,X}=1$, $\widetilde C=0.1$, $\alpha=2/3,1$ and $\tau=2^{-n}$ for $n=10,20,40,80,160,320$. Quadrature of $v^{-2\alpha/3}$ on $[1/2,1]$ is extended by exact dyadic-panel scaling. The inverse-square coefficient check fixes $\eta_c=2$. Frozen scalar controls solve only the energy quadrature of $\ddot\xi=-2/\xi^2-H/\xi^{5/3}$ with $(H,\mathcal E)=(1,0.7),(-0.5,0.7),(0,0.7)$ at $\xi=10^{-k}$, $k=3,6,9,12,18,24,36,48$. Its inverse speed is $[4/u+3H/u^{2/3}+1.4]^{-1/2}$; substituting $u=\xi z^6$ regularizes the integral on $z\in[0,1]$. Predicted corrections use Eq. (10), or $\mathcal E A^2/(5\eta_c)$ at power $4/3$ when $H=0$. Relative rule differences, cumulative analytic errors and final correction-amplitude errors must respectively be below $10^{-65},10^{-120},10^{-12}$; the last two-point correction slope has absolute error below $10^{-10}$. These are frozen-scalar controls, not numerical validation of the coupled branch in Eq. (10).
[under "6. Verification, limitations and conclusion"]
The 24 steady-identity cases form the Cartesian grid $(a,b)\in\{(2,1/2),(1.2,0.4),(3,-1/2)\}$, $\beta\in\{0.01,0.1,1,10\}$, $\mathcal R\in\{10,100\}$, with $S_{\rm sys}=10^8$, $\gamma=5/3$ and relative identity tolerance $3\times10^{-14}$. The nine clock controls use the same $(a,b)$ pairs and $\Gamma_{y,0}=1/2,1,2$ at $\bar C=2$, $\rho=3$, $P=4$; the six sign cases use $b=0,1/2,1/3,-1/2,2/3,3/4$. Four additional bremsstrahlung domain cases use $(\beta,\mathcal R,S_{\rm sys})=(10^{-6},100,10^8),(1,100,10^8),(1,10^{10},10^6),(100,10,10^7)$. Their geometry and inflow comparisons use the strict inequalities stated in Section 5, with $0.1$ as the illustrative aspect-ratio threshold.
[under "6. Verification, limitations and conclusion"] [block of 1599 characters not shown; it begins "**Code and data availability.** Original code, numerical outputs, figure sources…"]
[under "References"] [block of 1506 characters not shown; it begins "[5] T. Kalin, *Computational evidence for Thermodynamic consistency and closure…"]
[under "References"] [block of 167 characters not shown; it begins "[6] C. R. Harris, K. J. Millman, S. J. van der Walt et al., *Array programming w…"]
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