Self-as-an-End
SAE Black Hole Series · Paper 1

Area-Level Plateau and Self-Sufficient Window in a Frozen-Ledger Model
冻结账本模型中的面积级平台与自足窗

Han Qin (秦汉) · Independent Researcher · 2026
DOI: 10.5281/zenodo.20913514 · Full PDF on Zenodo · CC BY 4.0
Abstract

This is the first preregistered, reproducible computational test in the SAE black-hole series. We construct a $W\times W$ cylindrical stabilizer toy model and contrast two arms under a single measurement protocol: a frozen-ledger arm, in which bond openings follow a local rule and the radial depth of internal records is preserved; and a fully open scrambler arm, in which a global unitary scramble erases the distinguishability of the radial depth labels. What we obtain is a type-B computable structural divergence: the plateau entropy and the registered self-sufficient window of the frozen arm scale as $S_{\rm plat},\widehat\omega=O(W)$ (area level), while the scrambler arm scales as $S_{\rm half},\widehat\omega=O(W^2)$ (volume baseline); this is accompanied by a radial depth ladder in the frozen arm and depth-label erasure in the scrambler arm.

The principal results are organized along a spine and an edge. The spine is the area-level plateau, whose normalized collapse has a coefficient of variation of $0.0151$, measured across the three sizes from the medians of $S_{\rm plat}/W$. The edge is the frozen-versus-scrambler contrast of the self-sufficient window: we first establish the volume baseline of the scrambler, whose half-system entropy has a strict dimensional upper bound $M_0/2-1$, its near-saturation being consistent with Page-type typicality and the decoupling scale of random scrambling (this is the numerical baseline of the present control, not a per-sample consequence of Page's theorem for this local circuit); we then exhibit the registered self-sufficient window of the frozen arm, whose median ratio $\widehat\omega/S_{\rm plat}$ across the three sizes is $1.229$, $1.146$, $1.311$, lying within the prior structural band $[0.9,1.5]$. The theoretical support is a frozen-ceiling lemma, whose first inequality is a strict theorem within the stabilizer framework, while its area-level scaling is a conditional structural conclusion established by the data across the three sizes $W\in\{24,32,40\}$, not a proof of a $W\to\infty$ asymptotic law.

This paper observes three boundary stakes: it does not resolve the information paradox; it does not claim to replace any existing approach, nor does it adjudicate the rights and wrongs of the black-hole information problem; and it offers no direct empirical prediction. With respect to the three topological-closure mechanism candidates listed in Info-4, it provides a computable adjacent example, compatible rather than advancing, and does not select among the three. Six preregistered primary criteria pass; one supporting diagnostic fails and is retained as a negative result per the preregistration. This paper departs from a different ontological source and offers a line of thought for the consideration of colleagues.

Keywords: SAE; black-hole information-flow topology; stabilizer toy model; area-level scaling; self-sufficient window; frozen ceiling; preregistration; type-B structural divergence.

§1 Problem, Background, and Jurisdiction

§1.1 Background of the black-hole information problem

The black-hole information problem originates in a tension. Hawking showed in 1975 [1] that a black hole is not entirely black: its horizon radiates through quantum effects, with a nearly thermal spectrum. If the radiation were purely thermal, then once the black hole has fully evaporated, the information carried in by the infalling matter would seem to vanish with it; yet the unitarity of quantum mechanics requires information to be conserved. The two are in conflict, and this is the black-hole information paradox.

Page gave a criterion in 1993 from the side of unitarity [2,3]. If a black hole and its radiation form a pure state, then the entanglement entropy of the radiation subsystem should follow a particular trajectory: early in the evaporation, the radiation entropy rises with each emission; past a midpoint (now called the Page time), if unitarity holds, the entanglement entropy instead turns over and descends, eventually returning to zero. This rise-then-fall curve is now called the Page curve. A thermal spectrum predicts monotone growth without turnover; the descending branch of the Page curve is thus the imprint left by unitarity in black-hole evaporation.

In recent years there has been notable progress on the semiclassical-gravity side. The island formula and the replica-wormhole computation [4,5,6,7], within the framework of the quantum extremal surface, have reproduced the descending branch of the Page curve in the semiclassical gravity of curved spacetime. This approach is geometry-led: it admits additional saddle-point contributions in the gravitational path integral, so that the radiation entropy descends after the Page time as the quantum extremal surface is updated. It is a fruitful approach and has established its standing on the black-hole information problem (for a review, see [8]).

The approach taken here is not this geometry-led one, but a different ontological source. The SAE quantum-mechanics and information-theory series have advanced an ontological reading of the internal structure of black holes, whose essentials are set out below in the series note and in §2. The question of this paper is whether, departing from this different ontological source, one can construct a computable toy model in which a frozen ledger that retains internal records and a fully open scrambler exhibit a legible structural divergence. This paper does not adjudicate the rights and wrongs of the geometric approach, nor does it contend with it; it offers a different line of thought for the consideration of colleagues.

§1.2 Provenance of the problem and the question posed

The specific problem of this paper continues the opening left at §7 of SAE quantum-mechanics series P9, Pre-Closure Field Distribution [12]. P9 establishes the area law of entanglement entropy up to general regions of the vacuum, with the ontological reading that the area law arises from the locality of cross-boundary gluing together with the low-excitation topology of the vacuum baseline, and that local gluing alone yields only an upper bound, while a highly excited or thermal state may obey a volume law. P9 explicitly leaves the special boundary of the black hole ($S=A/4$, the Page curve, the island) to a future contact of the quantum-information series with a black-hole-information paper; this paper is the first step of that contact. Info-4, Black-Hole Information through the Causal Spectrum [13], lists the topological-closure mechanism of the Page curve as open, with the three candidates of phase transition, percolation, and SOC coexisting rather than derived.

The question thus arises: can one construct a computable toy in which a frozen ledger that retains memory and a scrambler with erased labels exhibit a legible area-level-versus-volume-level structural divergence, as the first computable continuation of the opening left at P9 §7? This question neither solves the black-hole information paradox nor adjudicates among the three candidates of Info-4; it asks whether the ontological reading of the area law established in P9 can be made manifest, in a computable stabilizer instance, as a structural distinction between frozen and scrambler.

§1.3 Contributions of this paper

This paper makes three contributions. First, it constructs a preregistered computable toy whose primary criteria and failure conditions are committed before the run, and whose conclusions can be reproduced by a third party holding the same code and the same manifest. Second, within this toy it obtains a type-B structural divergence: $O(W)$ for the frozen arm against $O(W^2)$ for the scrambler arm, together with the retention and erasure of the radial depth ladder; and it establishes a frozen-ceiling lemma as the theoretical support, whose strict part is a theorem within the framework and whose area-level scaling is a conditional structural conclusion. Third, it provides a computable adjacent example for the topological-closure problem posed in Info-4, compatible rather than advancing. What this paper actually obtains is the passing of six preregistered primary criteria together with the honest negative result of one supporting diagnostic; it is not an empirical proof of the black-hole ontology.

§1.4 Jurisdiction and boundary stakes

The jurisdiction of this paper must be stated up front in the introduction, demarcating what it does not do. This paper observes three boundary stakes. First, it does not resolve the information paradox; the structural divergence obtained is a computable fact internal to the toy, not a solution to the paradox. Second, it does not claim to replace any existing approach, nor does it adjudicate the rights and wrongs of the black-hole information problem; this paper and the geometry-led island approach are different ontological readings of the same phenomenon, the rights and wrongs of which await tests far beyond the present toy, and this paper offers only a line of thought without contending with existing approaches. Third, it offers no direct empirical prediction for LISA, CE, or ET; the present toy is a structural diagnostic in the stabilizer setting and does not connect to real curvature, energy, or the Hawking spectrum. These three boundary stakes are reiterated in this section, in §2, and in §6, and form the hard boundary of the paper. Whatever this paper does not compute lies outside its claims.


Series Note

This is a series-level note on the position of this paper within the SAE black-hole series and the upstream it inherits.

Method of the black-hole series

The SAE black-hole series takes the computable toy model as its method, placing the operationalizable parts of the black-hole ontological structures already advanced in the SAE quantum-mechanics and information-theory series into preregistered, reproducible computational tests. This is the first such paper in the series. The measure of the word "computational test" must be stated plainly: what this paper tests is a structural divergence internal to a stabilizer toy model, not an empirical proof of the black-hole ontology; what it obtains is a legible type-B structural divergence within the toy, together with the passing of its preregistered primary criteria and the honest negative result of one supporting diagnostic.

The method of the series observes four disciplines. First, the preregistered primary criteria and failure conditions are committed before the run and not revised afterward. Second, the engine, simulator, judge, driver, and preregistered ontology are each locked by hash, so that every reported conclusion can be reproduced by a third party holding the same code and the same manifest. Third, replay concordance across two implementations, together with an independent re-judgment by an independent implementation with its own logic, gives cross-corroboration beyond a single judge. Fourth, for any quantity internal to the toy, statements stop at the execution-semantics layer and are not extrapolated to black-hole physics.

The black-hole theme can be extended widely—the structure of the information paradox, the mechanism of the Page curve, the firewall, the decoding of Hawking radiation, the internal imprint on gravitational waves—and the series will unfold these in subsequent papers. Paper 1 establishes this programme and takes one clean structural result as the series' point of departure.

Inherited upstream

The inheritance of this paper rests chiefly on three sources, with the rest peripheral.

The direct upstream is QM P9, Pre-Closure Field Distribution [12], brought over directly from the quantum-mechanics series. Three things are inherited. First, the area law as a reinterpretation, which is the ontological source of the plateau and self-sufficient window of this paper. P9 establishes that the area law of entanglement entropy arises from the locality of cross-boundary gluing together with the low-excitation topology of the vacuum baseline, and states that local gluing alone yields only an upper bound, while a highly excited or thermal state may obey a volume law. The toy of this paper is precisely a computable instance of that reading. Second, the explicit interface at P9 §7. P9 establishes the area law up to general regions of the vacuum and explicitly leaves the special boundary of the black hole to a future contact of the quantum-information series with a black-hole-information paper; this paper is the first step of that contact. Third, the ontological vocabulary of the toy—ρ-OR capacity, cells and gluing, closure-addressable, the inannihilable remainder—derives from the $\{\mathfrak A_i,\rho_i,G_{ij}\}$ triple of P9; the remainder cell $\varepsilon\equiv1$ corresponds to P9's "remainder cannot be annihilated."

The black-hole-ontology side is Info-4, Black-Hole Information through the Causal Spectrum [13], the black-hole-information paper referenced at P9 §7. From it this paper inherits the reading of the black-hole interior as 3DD active plus 4DD inactive, Hawking radiation as a categorical lift, the three topological-closure mechanism candidates of the Page curve, and the firewall as a categorical boundary. Among these, the three mechanism candidates are the objects of the bounded interface in §4.6; this paper provides a computable adjacent example for them and does not select among the three.

The foundation is SAE Foundation [14], from which this paper inherits the physical-quantity ladder $L_0$ through $L_5$, ρ-OR and ρ-AND, the $L_3\to L_4$ closure equation, and the discrete prior.

The remaining upstream is peripheral. The methodological and terminological peripherals are Info-3 [16] (causal slot and the substrate-aggregation spectrum), Info-5 [16], and Info-6 [16] (gravitational-wave dynamics); the gravitational-ontology corroborations are Relativity P5 [17] (the phase transition of the horizon cell tensor) and Relativity P6 [17] (Kerr spiral closure, a future generalization direction of the present Schwarzschild toy). E=Ic³ derives from the mass-series convergence paper, The Nature of Information: E/c³ [15]. The black-hole ontology of this series further includes a set of images concerning the mass threshold and evaporation fate; as these do not enter the algorithm of the present toy, they are listed as questions for later in the series and not included in the body of this paper (see §7.2).

Epistemic discipline

This paper inherits the commitment grading and the firewall epistemic stance of the whole series. Every statement is graded by the strength of its commitment. The firewall epistemic stance holds that SAE does not derive any external conclusion, nor does that external conclusion prove SAE; the two frameworks correspond only on a shared structure. This paper is a structural diagnostic of a computable toy and does not claim empirical superiority over existing physics, nor does it give quantitative empirical predictions in the place of physicists. For all that is claimed, established, or erred, the responsibility lies with the author; the contribution of reviewers is recorded only in the acknowledgments.


§2 Operational Model and SAE Mapping

This section first defines the model clearly as a self-contained computable object, so that an external reader need accept no SAE ontology to reproduce it; it then gives the SAE ontological mapping; and finally it erects a firewall between the two. The section closes with a table listing what is placed into the model in advance and what is earned by production, to clarify the boundary between input and output.

§2.A Operational-model layer

The operational definition of the model is as follows, containing no ontological vocabulary. The substrate is a $W\times W$ cylindrical lattice carrying stabilizer qubits, evolving by phase-independent Clifford operations (the model structure is shown in Figure 1). Each dynamical step first applies Clifford gates on the open bonds, then selects the current outermost emittable cell, enters its index into the radiation sequence $R$, and moves the unemitted boundary of that column inward by one. The execution semantics of this emission must be stated plainly: the emission applies no additional quantum gate and builds no separate radiation register; it reclassifies the qubit of the selected cell from the unemitted subsystem into the radiation subsystem, the emitted qubit thereafter no longer participates in dynamical gates, and the entropy computation treats the qubits in the radiation sequence as the radiation subsystem.

The opening and closing of bonds follow a local or an open rule. The emergent-local arm determines the opening of each bond by the local opening rule of §3.1, with parameters fixed at $a_0=2,\,w=0.4$, and the radial depth of internal records is preserved. The control arm opens all non-remainder bonds and is a fully open random-Clifford scrambler; its evolution is globally unitary and does not erase information—what it erases is the distinguishability of the radial depth labels. Three diary–Ref Bell pairs are embedded in the system, at deep, mid, and shallow layers, to track when internal records are read out into the radiation. There is further a remainder cell $\varepsilon\equiv1$ that is never emitted and never touched by any gate. The formal definitions of all observables ($S_{\rm plat}$, $S_{\rm half}$, $t_{\rm exit}$, $\widehat\omega$, $\Delta$, etc.) are given in §3.

The identity of the control must be stated plainly: the control is a fully open random-Clifford scrambler control and not a synonym for the standard black-hole model. Its standing in this paper is that of a known Page-type volume baseline, detailed in §3.6 and §4.2.

§2.B SAE-mapping layer

Once the operational model is fixed, the SAE ontological mapping is given, listed in Table 1. The essentials: inactive bonds correspond to readout suspension, i.e. 4DD inactive; the active skin corresponds to the closure-addressable layer; the remainder cell corresponds to a toy encoding of Via Rho, i.e. the inannihilable remainder [12], tied to the memory prior of the $L_4$ closure layer; the single sequence of radiation readout corresponds to an abstract boundary readout channel. The black-hole interior of 3DD active plus 4DD inactive [13] maps to the frozen interior together with the active skin.

Table 1 Operational objects and the SAE ontological dictionary

Operational object Execution semantics (within the toy) SAE mapping Commitment level
inactive bondno Clifford gate applied; burial drives $p_{\rm open}\to0$readout suspension (4DD inactive)structural correspondence
active skinone-dimensional skin of outermost emittable cellsclosure-addressable layerstructural correspondence
frozen interiorqubits never having entered a post-prep gate ($F_t$)black-hole interior 3DD active + 4DD inactive [13]structural correspondence
remainder cell $\varepsilon\equiv1$a single cell never emitted, never gatedVia Rho (inannihilable remainder [12]), tied to the $L_4$ memory priorstructural correspondence
radiation readout sequence $R$the index sequence of emitted cells; subsystem reclassificationabstract boundary readout channelstructural correspondence
diary–Ref Bell pairentanglement of three-layer internal records with reference qubitsradial depth marking of internal recordsstructural correspondence

The commitment level is uniformly marked as structural correspondence, to clarify the demarcation: these are all structural relations within the stabilizer model and their correspondence with the SAE ontology, not empirical claims about the black-hole ontology.

One discipline bears reiterating: all the above mappings are correspondences of structure, not claims about the black-hole ontology. What the toy presents is a structural relation within the stabilizer model; its commonality with the black-hole ontology stops at the mapping and does not pass beyond it to become a proof of the ontology.

§2.C Firewall

This is the crux of the section, and a clear firewall must be erected. The radiation-readout reclassification in the toy is not a gravitational-wave model, nor a dynamical model of microscopic Hawking modes. That a single channel maps to a boundary readout reclassification is at most an information-flow-topology homomorphism and cannot be written as a realization of a physical channel. The black-hole images of this series concerning the mass threshold and evaporation fate do not enter the algorithm of the toy; the body of this paper does not develop these three, listing them at most as later questions in §7.2.

§2.D Boundary stakes

This paper observes three boundary stakes, not to be crossed, reiterated here up front. First, it does not resolve the information paradox. Second, it does not claim to replace any existing approach, nor adjudicate the rights and wrongs of the black-hole information problem. Third, it offers no direct empirical prediction for LISA, CE, or ET. The three boundary stakes are reiterated in §1, in this section, and in §6, and form the hard boundary of the paper.

§2.E The boundary between input and earned

To forestall a standard objection—that the freezing is placed in by rule, and that the area-level plateau and delayed release may be merely "assumptions taken as numbers"—we set out here, in plain view, the input of the model and the output of production.

Placed into the model in advance Earned by production
the local sigmoid freezing rulethe cross-size collapse of $S_{\rm plat}/W$ (three-median CV $=0.0151$)
the shallow prepthe area-level-versus-volume-level divergence between frozen and control
the radial positions of the three diariesthe $15/15$ depth ladder per size, and the depth-label erasure of the control
the one-cell-per-step emission sequencethe existence of a continuous self-sufficient window, and the cross-$W$ stability of $\widehat\omega/S_{\rm plat}$
the remainder cell, forbidden to emit or be gatedthe $110/110$ semantic conservation of K0

This table does not weaken the result; it separates rule-input from structural-output most clearly. What is placed in are rules and arrangements; what is earned is cross-scale scaling behavior and a legible divergence, the latter not read off directly from the former but manifest only through the computation of production.


§3 Mathematical Quantities, Analytic Constraints, and Preregistration

This section distills the four quantities used by the model into mathematical definitions from the frozen implementation, gives two frozen-ceiling lemmas, establishes the volume baseline of the control, and states the rules of preregistration and data inclusion. The section observes two disciplines. First, everything reported by the frozen engine is a registered quantity under the protocol; an ideal global quantity may be defined separately, but the two must be written distinctly. Second, what the frozen ceiling constrains is the area-level scale of the radiation entropy; it does not by itself imply the continuous locality of the self-sufficient window in the emission order, which has a separate argument and is tested by data.

§3.1 Local opening rule

Let the highest radial coordinate not yet emitted in column $\theta$ after step $t$ be $H_t(\theta)\equiv\mathtt{col\_top}[\theta]$. For a bond $b$, let its code's radial anchor be $r_a(b)=\lfloor\bar r_b\rfloor+1$. A radial bond spans one column, an angular bond spans two adjacent columns. For any column $\theta$ it spans, define the local overburden above the bond

$$d_t(b,\theta)=\bigl[H_t(\theta)-r_a(b)+1\bigr]_+,\qquad [x]_+\equiv\max(0,x),$$

so the local burial reading in the engine is

$$o_{\rm loc}(b,t)=\frac{1}{|C_b|}\sum_{\theta\in C_b}d_t(b,\theta),$$

where $C_b$ has one column for a radial bond and two for an angular bond. Set further

$$\chi_b(t)=\mathbf 1[b\notin E_{\rm rem}]\prod_{v\in\partial b}\mathbf 1\!\left[r(v)\le H_t(\theta(v))\right],$$

i.e. the bond does not meet the remainder cell, and both its endpoints are not yet emitted. One semantic point must be clarified: what the final factor of $\chi_b$ tests is whether the endpoints are still present (not yet emitted, still belonging to the current lattice), not whether the endpoints are unfrozen; opening and freezing are decided independently by the Bernoulli threshold below. For a fixed quenched random number $u_b\sim\mathrm{Uniform}[0,1)$, the actual opening variable is

$$X_b(t)=\chi_b(t)\,\mathbf 1\!\left[u_b<\sigma\!\left(\frac{a_0-o_{\rm loc}(b,t)}{w}\right)\right],$$

and taking the conditional probability over the quenched disorder,

$$p_{\rm open}(b,t)=\chi_b(t)\,\sigma\!\left(\frac{a_0-o_{\rm loc}(b,t)}{w}\right),\qquad\sigma(x)=\frac{1}{1+e^{-x}}.$$

This corresponds exactly to the engine's oA/oB/o, the fixed $u_b$, and the threefold terminal mask. While the endpoints are still present,

$$\frac{\partial p_{\rm open}}{\partial o_{\rm loc}}=-\frac{\chi_b(t)}{w}\,\sigma(1-\sigma)\le 0.$$

Thus the greater the burial, the lower the opening probability; as emission lowers $H_t(\theta)$, $o_{\rm loc}$ is non-increasing, and the opening probability of a fixed bond is non-decreasing. In other words, while its endpoints remain, a quenched bond only loosens from frozen toward open, and does not re-close by the same overburden mechanism; once an endpoint is emitted, $\chi_b=0$ and the bond exits the dynamical graph. This monotonicity is strict within the framework. The production main arm fixes $a_0=2,\,w=0.4$.

§3.2 Stabilizer subregion entropy

A globally pure stabilizer state is represented by $n$ independent stabilizer generators, with binary tableau $G\in\mathbb F_2^{n\times 2n}$ [9,10] and column order $(X_0,\ldots,X_{n-1}\mid Z_0,\ldots,Z_{n-1})$. For a qubit subset $A$, let $G|_A$ be the matrix keeping all $X$ and $Z$ columns corresponding to $A$. The subregion entropy used by the model is

$$\boxed{\,S(A)=\operatorname{rank}_{\mathbb F_2}(G|_A)-|A|\,}$$

in bits, the engine computing this rank by bit-packed $\mathbb F_2$ Gaussian elimination. For a pure stabilizer state this is the von Neumann entanglement entropy, so $0\le S(A)\le\min\{|A|,n-|A|\}\le|A|$, together with subadditivity for disjoint subregions, $S(A\cup B)\le S(A)+S(B)$. All mutual information in this paper is defined accordingly: $I(A:B)=S(A)+S(B)-S(A\cup B)$. This formula and its properties are strict within the framework, proved in Appendix A.1.

§3.3 Exit time

Let the actual emission order be $(e_0,e_1,\ldots,e_{n_E-1})$, $n_E=M_0-1$, and define the continuous radiation prefix $R_{[0,b)}=\{e_0,\ldots,e_{b-1}\}$. Let the reference qubit of the $k$-th diary be $\mathrm{Ref}_k$. The reference qubit never participates in subsequent gates, and always $S(\mathrm{Ref}_k)=1$; its prefix mutual information is

$$I_k^{\rm pre}(b)=I(\mathrm{Ref}_k:R_{[0,b)})=S(R_{[0,b)})+1-S(R_{[0,b)}\cup\{\mathrm{Ref}_k\}).$$

The exit time is defined as

$$\boxed{\,t_{\mathrm{exit},k}=\min\{b\in\{1,\ldots,n_E\}:I_k^{\rm pre}(b)=2\}.\,}$$

The code searches by bisection on the condition $I\ge2$; the mutual information of a single-qubit reference has upper bound exactly $2$ bits, and stabilizer entropy is integer, so $I\ge2$ and $I=2$ are entirely equivalent.

This threshold has a strict meaning. Let $C$ be the global complement of $R_{[0,b)}$; then the globally pure state satisfies $I(\mathrm{Ref}_k:R_{[0,b)})+I(\mathrm{Ref}_k:C)=2S(\mathrm{Ref}_k)=2$, so $I(\mathrm{Ref}_k:R_{[0,b)})=2$ iff $I(\mathrm{Ref}_k:C)=0$, i.e. the reference qubit is completely decoupled from the rest of the system and all its purification is carried by that radiation prefix. In the stabilizer language, this is equivalent to: after a Clifford transformation internal to the radiation subsystem, a logical qubit can be extracted within the prefix that forms a Bell pair with $\mathrm{Ref}_k$. Hence $I=2$ is the necessary-and-sufficient threshold for the Bell purification of the diary to have entered the radiation completely, not an arbitrary empirical threshold. This criterion is strict, proved in Appendix A.2.

§3.4 Self-sufficient window and the registered estimator

For any continuous radiation window $R_{[a,b)}=\{e_a,\ldots,e_{b-1}\}$, define $I_k(a,b)=I(\mathrm{Ref}_k:R_{[a,b)})$. The ideal global self-sufficient window length may be defined as

$$\omega_k^\star=\min_{0\le a

meaning the shortest window length needed for the $k$-th diary to be fully purified if only a continuous segment of the radiation record is handed to the decoder.

What the production engine actually reports, however, is not the unconstrained $\omega_k^\star$ but a registered estimator under the frozen protocol. The current implementation computes $\widehat\omega_0$ only for the deep diary ($k=0$). Centering on $t_e=t_{\mathrm{exit},0}$, it fixes the search band $a\in\mathcal D=[\max(0,t_e-10W),\,\min(n_E-2,t_e+2W)]\cap\mathbb Z$. For each start $a$, define $b_{\min}(a)=\min\{b\ge\max(a+2,t_e):I_0(a,b)=2\}$. The engine first finds $b_{\min}(a)-a$ on a coarse grid of step $4$, then refines pointwise in the $\pm4$ neighborhood of the optimal coarse start, and selects the smaller $a$ among windows of equal length.

The body must write two quantities distinctly: $\omega_0^\star$, the ideal global quantity, and $\widehat\omega_0$, the actual quantity measured under the frozen protocol. For fixed $a$, $I_0(a,b)$ is non-decreasing in $b$, so the bisected $b_{\min}(a)$ is exact. And since $R_{[a_2,b)}\subset R_{[a_1,b)}$ for $a_1

$$\boxed{\,\omega_{\mathcal D}^\star\le\widehat\omega_0\le\omega_{\mathcal D}^\star+3\,}$$

provided the run is not marked protocol-invalid. Proved in Appendix A.3. Thus the current protocol gives an additive error of at most $3$ emission steps within the registered search band, and does not automatically prove the global strict equality $\widehat\omega_0=\omega_0^\star$. All self-sufficient-window numbers in the body are written as the registered self-sufficient window $\widehat\omega$, not as the unqualified global minimum window. This additive bound is strict; the global equality $\widehat\omega=\omega^\star$ lies beyond the boundary.

§3.5 Frozen ceiling

After step $t$, partition the lattice and reference qubits into four disjoint subsystems: $R_t$, the emitted qubits; $A_t$, qubits not yet emitted and having entered a post-prep gate; $F_t$, qubits not yet emitted and never having entered a post-prep gate; and $Q=\{\mathrm{Ref}_1,\ldots,\mathrm{Ref}_{N_{\rm ref}}\}$. Emission only reclassifies a qubit into $R_t$, an emitted qubit no longer participates in gates, and the global tableau remains pure throughout.

Lemma 1 (strict frozen ceiling). For every dynamical time $t$,

$$\boxed{\,S(R_t)\le|A_t|+S(F_t)+N_{\rm ref}.\,}$$

Moreover, let $\rho^{(0)}$ denote the state at the completion of the shallow prep, when the evaporation dynamics properly begin; then

$$\boxed{\,\rho_{F_t}(t)=\rho^{(0)}_{F_t},\qquad S_t(F_t)=S_0(F_t).\,}$$

The second equality shows that the frozen ledger does not continue to evolve; as the horizon moves inward, what changes is which qubits still belong to $F_t$, not the records retained within $F_t$ being rewritten by post-prep gates. Both equalities of Lemma 1 depend on neither randomness nor a Page assumption, and are strict conditional mathematics within the framework, proved in Appendices A.4 and A.5. The conclusion is stronger than invariance of entropy: not only is the entropy invariant, the entire reduced density operator is invariant.

Lemma 2 (finite-depth cut bound). Suppose that before preparation there are only some fixed Bell pairs, the rest of the qubits being product states; let $B(F)$ be the number of these seed Bell pairs with exactly one end in $F$, and $\partial_E F$ the set of bonds in the lattice graph used by the preparation circuit that cross $F$ and its complement. Then

$$\boxed{\,S_0(F)\le B(F)+2d_{\rm prep}\,|\partial_E F|.\,}$$

In the present model $B(F)\le N_{\rm ref}+1$, the extra $1$ coming from the remainder cell and its Bell partner. Proved in Appendix A.6.

If, within the plateau interval considered, there exist constants $\alpha,\beta$ independent of $W$ such that $|A_t|\le\alpha W$ and $|\partial_E F_t|\le\beta W$, then $S(F_t)\le 2d_{\rm prep}\beta W+N_{\rm ref}+1$, and

$$\boxed{\,S(R_t)\le\bigl[\alpha+2d_{\rm prep}\beta\bigr]W+2N_{\rm ref}+1.\,}$$

This is the area-level frozen ceiling. Here $\beta$ is the cut-density of the frozen boundary. If the model parameters $a_0,w$ and the local gluing graph are fixed, they may be absorbed into the constant, abbreviated $\kappa(d_{\rm prep})$; but if different $a_0,w$ are compared, $\kappa$ cannot in general be said to depend on $d_{\rm prep}$ alone. This also explains why the coefficient for different $a_0$ may drift: what the ceiling constrains is the order of magnitude, not a precise parameter-free coefficient.

The limit must be stated plainly. That $|A_t|,|\partial_E F_t|=O(W)$ holds in the plateau interval of the emergent-local arm is a structural condition within the model, consistent with the output of K1, not an unconditional theorem derived directly from the local rule; hence the $S_{\rm plat}=O(W)$ that follows is a conditional structural conclusion. Across the three sizes tested $W\in\{24,32,40\}$, production gives a coefficient of variation of $0.0151$ for the medians of $S_{\rm plat}/W$, consistent with the area-level condition above; this is not a proof of a $W\to\infty$ asymptotic law.

Finally, one logical demarcation must be stated. What the frozen ceiling constrains directly is the radiation entropy and the available capacity; it does not by itself prove that the information must be concentrated in $O(W)$ continuous positions in the emission order. The continuous locality of the self-sufficient window $\widehat\omega=O(W)$ is another matter, established chiefly by the G1 data within the band in §4.3; the mechanism of the skin capacity filling up is a structural motivation for it, not an independent strict proof. The ceiling gives the area-level scale of the window law, and G1 gives the continuous locality of the window together with data. The spine gives the scale, the edge gives the locality, and here the two divide their labor.

§3.6 The volume baseline of the fully open control

The control arm opens all non-remainder bonds, and a local post-prep Clifford circuit acts continuously on all not-yet-emitted qubits, so there is no constraint maintaining a low-depth frozen ledger. Here $A_t$ is volume-level in the middle stage, and the frozen ceiling gives only the loose bound $S(R_t)=O(M_0)=O(W^2)$.

Since the remainder cell is never emitted, the total emission count is $n_E=M_0-1$. For even $M_0=W^2$, the qubit count of the half radiation prefix is exactly $h=\lfloor n_E/2\rfloor=M_0/2-1$. So $S(R_{[0,h)})\le h$ is an exact dimensional upper bound. This $-1$ comes strictly from the count of one qubit never emitted, consistent with the static bookkeeping of the remainder cell; the Bell partner of the remainder cell serves to maintain the entanglement-ledger semantics of $\varepsilon=1$ and does not by itself imply this $-1$.

The measure of the relation between control and Page must be observed. Page's original result treats the average subsystem entropy of a Haar-random pure state; the control evolution of this paper is a local Clifford circuit varying with time and the open network, and cannot without argument be equated with uniform Clifford sampling. Hence the statement of this paper: the half-system entropy of the control has a strict dimensional upper bound $M_0/2-1$ (this is a count); its near-saturation and $\operatorname{median}\,\widehat\omega_{\rm ctrl}/(M_0/2)=1.000$ are consistent with Page-type typicality and the decoupling scale of random scrambling (this is the numerical baseline of the present control, not a per-sample consequence of Page's theorem for this local circuit). The half-system entropy medians of the control across the three sizes are $287$, $511$, $799$, corresponding exactly to $M_0/2-1$. Hence the standing of the control in this paper is that of a known Page-type volume baseline; the new content of this toy lies not in the control itself but in the area-level plateau and area-level self-sufficient window that the frozen arm presents under the same measurement protocol.

§3.7 Preregistration, data inclusion, and the protocol-invalid rule

The criteria and failure conditions of this paper are committed before production, frozen in the preregistered ontology and locked by hash, not revised after the run. The primary criteria are six: K0 semantic conservation, K1 area-level plateau collapse, K2 depth ladder, K4 control volume baseline, G1 self-sufficient-window band, and G2 skin-capacity monotonicity. The supporting diagnostics are two: K3 front sharpening and K5 two-sided band; neither blocks the primary criteria. The identity, preregistered threshold, and final result of each criterion are collected in Table 2.

The main grid of production is $W\in\{24,32,40\}$ times $\{$emergent($a_0{=}2$), control$\}$ times $15$ seeds, totaling $90$ rows; the capacity arm is $W24$ times emergent times $a_0\in\{1,3\}$ times $10$ seeds, totaling $20$ rows; $110$ in all. The data-inclusion rule is as follows. Runs of the two boundary-invalid types $\mathtt{left\_boundary}$ and $\mathtt{right\_search\_boundary}$ are excluded from the window statistics and counted proportionally into the invalid fraction; if that fraction reaches its threshold (8 for a cell of size 15, 6 for size 10), the failure condition is triggered. $\mathtt{no\_window}$ and $\mathtt{other\_protocol\_error}$ are different: they are not ordinary invalids but substantive failures, do not enter the invalid-fraction statistics, and directly trigger Death-5. A right endpoint reaching $n_E$ with the start within the band is a physical late window and not marked invalid. The final round has only two $\mathtt{left\_boundary}$ runs (one seed at $W24$, one at $W40$), each below its cell threshold, not triggering the failure condition and excluded from the window statistics; there is no $\mathtt{no\_window}$.

The architecture of reproducibility is as follows. The engine, simulator, judge, driver, and preregistered ontology are each locked by SHA-256, together with the hashes of the spec, the bond enumeration, and the frozen environment. The judge is of zero-trust design: anyone holding the same judge code and the same manifest reproduces the same judgment. The final round passed replay concordance across two implementations, together with an independent re-judgment from the original manifest by an independent implementation with its own logic. The full record of the hardening rounds is placed in the supplementary material, not in the body.


§4 Results

The results of this section are presented along a spine and an edge. The spine is the area-level plateau, the hardest normalized collapse of the paper; beneath it the volume baseline of the control is established first, so the target of contrast is fixed; then the frozen-versus-control contrast of the self-sufficient window is exhibited, which is the edge; then the retention and erasure of the depth ladder, together with the monotonicity of skin capacity. The spine and the edge share one quantity displayed twice: the same mid-stage entropy $S_{\rm mid}$, measured for its height at the spine and for its width at the edge.

§4.1 Spine: the area-level plateau K1

The evolution of the frozen arm shows in its middle stage an extremely steady plateau, whose height is $S_{\rm plat}$. Across the three sizes tested $W\in\{24,32,40\}$, $S_{\rm plat}/W$ collapses steadily. Measured by the coefficient of variation of the three medians of $S_{\rm plat}/W$ ($4.34$, $4.48$, $4.34$), it is $0.0151$, far below the preregistered threshold of $0.2$, consistent with area-level $O(W)$ scaling (the stepwise entropy curve is shown in Figure 2, the plateau collapse in Figure 3). The measure must be observed: this is collapse and consistency within three sizes, not a proof of a $W\to\infty$ asymptotic law; its theoretical support is the frozen ceiling of §3.5, which constrains the area-level scale of the radiation entropy. This area-level scaling is a conditional structural conclusion, the condition being $|A_t|,|\partial_E F_t|=O(W)$ in the plateau interval of the emergent-local arm.

In contrast is the half-system entropy of the control arm. The cell medians of the control across the three sizes are $287$, $511$, $799$, falling exactly on $M_0/2-1$. This $-1$ offset is consistent with the static bookkeeping of the single forbidden-to-emit remainder cell $\varepsilon\equiv1$; the measure must be observed—it is consistency, not a determinate consequence of the remainder cell. Its strict provenance is in §3.6: the total emission count is $n_E=M_0-1$, and the qubit count of the half prefix is exactly $\lfloor n_E/2\rfloor=M_0/2-1$, an exact dimensional count. The area level of the frozen and the volume level of the control are distinguished on this $1+1$-dimensional discrete stabilizer network, without any assumption of a higher-dimensional holographic duality.

§4.2 The volume baseline of the control K4

Before exhibiting the contrast of the self-sufficient window, the volume baseline of the control must be established, so the edge has a target. The self-sufficient window of the control satisfies $\operatorname{median}\,\widehat\omega_{\rm ctrl}/(M_0/2)=1.000$ across all three sizes. The identity of this window must be stated plainly. The half-system entropy of the control has a strict dimensional upper bound $M_0/2-1$, which is a count; its near-saturation and the approach of $\widehat\omega_{\rm ctrl}/(M_0/2)$ to unity are consistent with Page-type typicality and the decoupling scale of random scrambling, the numerical baseline of the present control, not a per-sample consequence of Page's theorem for this finite-depth local circuit. The new content of this toy lies not in the control itself but in what the frozen arm presents under the same measurement protocol. With this volume baseline established, the frozen contrast of §4.3 has its target.

§4.3 Edge: the unified self-sufficient-window contrast G1

This is the edge of the model, the most discriminating frozen-versus-control contrast of the paper. One beam of the spine-edge bridge must first be carried: the plateau of §4.1 is not merely the height of the area ledger; it is the very ruler of the self-sufficient window of this section. The same $S_{\rm mid}$, measured for its height at the spine and for its width at the edge; the self-sufficient window of the frozen arm scales by this area-level plateau, while the window of the control scales by $M_0/2$.

The registered self-sufficient window $\widehat\omega$ needed to collect for the purification of the deep diary achieves a clear scaling collapse in the frozen arm. The median ratios $\widehat\omega/S_{\rm plat}$ across the three sizes are $1.229$, $1.146$, $1.311$, all within the leading structural band $[0.9,1.5]$, with a cross-$W$ range of only $0.165$, below the preregistered $0.2$ (see Figure 4). The frozen self-sufficient window scales by area, about $1.2\cdot S_{\rm plat}$; this coefficient is a framework-level fluctuating quantity, not a precise constant, its fluctuation statistics given in §5.2. And the window of the control scales by $M_0/2$, the Page-type volume baseline of §4.2. Hence area window against volume window, distinguished under the same protocol.

Here one demarcation must be stated, the most crucial restraint of the section. The area-level scaling $\widehat\omega=O(W)$ is not derived directly from the frozen ceiling of §3.5. What the ceiling constrains is the area-level scale of the radiation entropy and the available capacity; it does not by itself prove that the information must be concentrated in $O(W)$ continuous positions in the emission order. The continuous locality of the self-sufficient window is established chiefly by the data of the present grid within the band; the mechanism argument of the skin capacity filling up is a structural motivation for it, not an independent strict proof. The ceiling gives the area-level scale of the window law, G1 gives the continuous locality of the window together with data; the spine gives the scale, the edge gives the locality, and here the two divide their labor. Hence the area-level conclusion of G1 in this section is a conditional structural conclusion, established by data testing, not derived unconditionally from the lemma.

One more point must be made, lest a reviewer ask at first sight. The band of G1 in this section is assessed specifically on the $a_0=2$ grid of production. The two grids $a_0\in\{1,3\}$ serve only the monotonicity of G2 below and are not subject to the band of G1. The reason is that the coefficient $c=\widehat\omega/S_{\rm plat}$ drifts with $a_0$. In the capacity arm, the median ratio at $a_0=1$ is about $1.257$, and individual seeds may rise to about $1.607$; this shows the coefficient depends on $a_0$, so the band of $a_0=2$ must not be extrapolated as a rule common to the three arms. This accords with the conclusion of §3.5: the ceiling constrains the order of magnitude, not a precise parameter-free coefficient; with different $a_0$ the boundary constant differs, and the coefficient drifts accordingly.

§4.4 K2 depth ladder and the control's depth-label erasure

The frozen arm preserves the radial depth label. The exit-time order of the deep, mid, and shallow diaries forms a strict ladder in the frozen arm, with the deep emitted latest and the shallow earliest in all $15$ seeds of each size, $15/15$ throughout (see Figure 5, left). The range of the same order in the control arm is only $0.000$ to $0.001$, the distinguishability of deep from shallow being erased. The measure must be observed: the control is a globally unitary evolution and does not erase information—what it erases is the distinguishability of the depth labels. The retention of the frozen and the erasure of the control are distinguished here: the frozen ledger retains the radial depth of internal records, while the scrambler flattens its labels. The execution semantics of this result are strict, the statement stopping at the exit-time order within the toy, not extrapolated to black-hole physics.

§4.5 G2 skin-capacity monotonicity

As the skin capacity $a_0$ increases, the median of the self-sufficient window increases strictly. The median $\widehat\omega$ for the three grids $a_0\in\{1,2,3\}$ is $98.5$, $130$, $151$, strictly monotone. This section stops at this one statement, that the median increases strictly with $a_0$; it is not extended to per-seed monotonicity, nor to separation of distributions, nor to near-non-overlap. This monotonicity is a conditional structural conclusion, established by the three grid medians.

§4.6 The bounded interface with Info-4

The area-level $O(W)$ of the frozen against the volume-level $O(W^2)$ of the control obtained by this toy is compatible at the structural level with the three topological-closure mechanism candidates listed in Info-4, providing a computable adjacent example for them. The measure of this interface must be observed to the utmost restraint. By adjacent example is meant that this toy shows a local frozen network and a fully open scrambler can produce a clear area-level-versus-volume-level divergence of information flow; it does not select among the three candidate mechanisms of phase transition, percolation, and SOC, nor does it constitute evidence for any one of them. The word compatible may be kept; the word corroboration is not taken.

What is not done in this section is stated plainly. This production did not test the critical exponents of phase transition, did not test the $4/7$ of gradient percolation, did not test SOC, did not test the replica or island saddle, and did not generate the dynamics of a real Page curve. This toy, with respect to Info-4, is compatible rather than advancing; it does not replace the replica-wormhole computation, nor resolve the information paradox. This paper departs from a different ontological source and offers a computable line of thought for the consideration of colleagues; the two frameworks are compatible only on the area-level-versus-volume-level scaling structure, and do not pass beyond it to prove each other.


§5 Negative Results, Finite Size, and Model Dependence

This section sets out, in concentration, the negative results and the genuine scientific limitations of this paper, not shadowing the negative with the light of the positive. The preregistered failure conditions being committed in advance, the negative results obtained are reported honestly and not revised after the fact.

§5.1 The partial support of K3 front sharpening

What K3 tests is whether the seed-to-seed spread of the deep-diary exit time, together with the rise-width of its release window, sharpens with size. The object of K3 must first be clarified, lest it be confused with K2: K3 tests the finite-size trend of the exit-spread and rise-width of the single deep-diary layer, not the ordinal sharpening of the three deep, mid, and shallow diaries; the latter is what K2 tests, and K2 passes $15/15$ in each of the three sizes.

The result of K3 is partial support. The seed-to-seed spread of the deep-diary exit time sharpens with size, its standard deviations being $0.0525$, $0.0289$, $0.0219$, monotonically decreasing. But the rise-width of its release window does not form a strictly monotone finite-size sequence, its values being $0.0730$, $0.0381$, $0.0563$, with a reversal rebound at $W40$ (see Figure 5, right). So the front sharpening obtains only partial support: the trend of narrowing spread holds, while the monotonicity of the rise-width does not. K3 is a supporting diagnostic, not a necessary condition of the primary criteria; its failure is reported honestly and does not overturn the conclusion of the primary criteria. This negative result awaits inspection at larger sizes or with finer front characterization.

§5.2 The random fluctuation of the coefficient c

The ratio of the self-sufficient window to the plateau, $c=\widehat\omega/S_{\rm plat}$, is a fluctuating structural quantity, not a precise constant. This fluctuation must be stated transparently. The criterion of G1 looks at the median of the cell, not at any single seed. The distribution of $c$ across the three sizes is as follows: at $W24$ the range is $[0.992,1.524]$, the interquartile range $[1.153,1.400]$; at $W32$ the range is $[0.965,1.457]$, the interquartile range $[1.072,1.284]$; at $W40$ the range is $[1.055,1.605]$, the interquartile range $[1.248,1.427]$. The single-seed spread is evidently significant, while the three medians $1.229$, $1.146$, $1.311$ all fall steadily within the band. By way of a single-seed example, the $c$ of seed s330 is $1.605$ at $W40$ and $0.992$ at $W24$, swinging to both ends across sizes; this is not a counterexample to the criterion but precisely the manifest proof that $c$ is a fluctuating quantity. So $c$ is marked as a framework-level fluctuating quantity, not a precise constant. This accords with the conclusion of §3.5: the frozen ceiling constrains the order of magnitude, not a precise parameter-free coefficient.

§5.3 Concentrated scientific limitations

The scientific limitations of this paper are concentrated as follows, five in all. First, the sizes tested are only three, $W\in\{24,32,40\}$, insufficient to fix an asymptotic exponent; what this paper claims stops at collapse and consistency within three sizes, not a $W\to\infty$ asymptotic law. Second, the rise-width of K3 is non-monotone, the front sharpening obtaining only partial support. Third, the coefficient $c$ has evident random fluctuation, not a precise constant. Fourth, model dependence: the conclusions of this toy hinge on the specific choices of the cylindrical topology, Clifford evolution, shallow prep, one-cell-per-step emission, and the like; change one, and the conclusion need not hold as before. Fifth, this toy does not connect to real curvature, energy, or the Hawking spectrum, its commonality with black-hole physics stopping at the mapping of information-flow topology, not reaching a realization of dynamics. The report of protocol-invalid runs has been placed in the data-inclusion rule of §3.7, being a report of the judgment protocol and not a scientific limitation, hence not listed in this section.


§6 Discussion and Scientific Status

§6.1 The type-B computable structural divergence

What this paper obtains is a type-B computable structural divergence. Its content: under the same measurement protocol, the frozen-ledger arm presents area-level $S_{\rm plat},\widehat\omega=O(W)$, and the control scrambler arm presents volume-level $S_{\rm half},\widehat\omega=O(W^2)$; accompanied by the depth ladder of the frozen and the depth-label erasure of the control. By type-B is meant that this is a compatibility of structure, which may fail at the physical level; what this paper establishes is a structural divergence within the stabilizer framework, not an empirical proof of the black-hole ontology. Its strict part (the dimensional count, the first inequality of the frozen ceiling, the Bell criterion of $I=2$, and the like) is a theorem within the framework; its area-level-scaling conclusion is a conditional structural conclusion; its extrapolation to real black holes lies beyond the boundary.

§6.2 Reiteration of the three boundary stakes and the exclusions

The three boundary stakes are reiterated here a third time, forming the hard boundary of the paper. First, this paper does not resolve the information paradox. Second, it does not claim to replace any existing approach, nor adjudicate the rights and wrongs of the black-hole information problem. Third, it offers no direct empirical prediction for LISA, CE, or ET. Beyond these three, several things must be excluded plainly: this paper gives no operational decoding of real Hawking radiation, and generates no dynamics of a real Page curve. Whatever this paper does not compute lies outside its claims.

§6.3 The firewall epistemic stance and the posture of this paper

This paper observes the firewall epistemic stance. The toy of SAE does not derive the Page curve, nor does the Page curve prove SAE; the two are compatible only on the area-level-versus-volume-level scaling structure. This compatibility is a computable adjacent example, not an adjudication among the three candidate mechanisms, nor an advancing of the paradox. This paper, with respect to existing black-hole theory, continues the opening left at QM P9 §7 and gives the first preregistered, reproducible frozen-versus-scrambler computational instance. This paper acknowledges the standing of the island and replica-wormhole approaches on the black-hole information problem, and departs from a different ontological source to offer a different line of thought. P9 gives the ontological reading of boundary gluing; this paper gives the first preregistered, reproducible frozen-versus-scrambler computational instance; the two each keep to their part. This paper does not contend with existing approaches, but invites colleagues to consider this different avenue.


§7 Remainder and Outlook

§7.1 Remainder

This paper leaves two remainders for later inspection. First, the front sharpening of K3, whose rise-width is non-monotone in finite size, awaiting inspection at larger sizes or with finer characterization. Second, the fluctuation statistics of $\widehat\omega/S_{\rm plat}$ of G1, the structure of whose seed-to-seed spread awaits more systematic statistical characterization.

§7.2 Subsequent directions of the black-hole series

This paper being the opening of the black-hole series, the subsequent directions are left here in brief. First, generalization to Kerr, inheriting the spiral closure of Relativity P6, extending the present Schwarzschild toy to rotating black holes. Second, a computable toy of the ringdown internal imprint, inheriting the gravitational-wave dynamics of Info-6. Third, scaling extrapolation to larger $W$, to inspect whether the consistency within three sizes extends to larger sizes. This series further holds a set of ontological images concerning the black-hole mass threshold and evaporation fate; as these do not enter the algorithm of the present toy, they are listed as questions for later in the series and not included in the claims of the body of this paper.

§7.3 The operationalization of the remainder within the toy

The remainder cell $\varepsilon\equiv1$ of this paper is an operationalization within the toy of the concept of construct-and-remainder. It is never emitted and never touched by a gate in the stabilizer evolution, maintaining the entanglement-ledger semantics of $\varepsilon=1$. One causal point must be clarified: the $-1$ offset of the control half-system entropy comes from the dimensional count of one qubit never emitted ($n_E=M_0-1$, hence $\lfloor n_E/2\rfloor=M_0/2-1$), not derived by itself from the Bell pairing of the remainder cell; the Bell pairing maintains the entanglement semantics of the remainder, the dimensional count gives the $-1$, and the two must not be conflated. This operationalization brings the ontology of the inannihilable remainder [12] down to a concrete computable object. The methodological significance of this operationalization awaits sufficient testing in later work of the series before its general formulation is discussed; this paper stops at stating the fact of this operationalization.


§8 Conclusion

This paper constructs a $W\times W$ cylindrical stabilizer toy model and obtains, under the same measurement protocol, a type-B structural divergence between the $O(W)$ area-level plateau and self-sufficient window of the frozen-ledger arm and the $O(W^2)$ volume-level baseline of the control scrambler arm, accompanied by the depth ladder of the frozen and the depth-label erasure of the control. Six preregistered primary criteria pass; one supporting diagnostic (K3 front sharpening) fails and is retained as a negative result per the preregistration. This paper establishes a frozen-ceiling lemma as the theoretical support for the area-level scale, whose first inequality is strict and whose area-level scaling is a conditional structural conclusion established by the data across three sizes. This paper continues the opening left at QM P9 §7, departing from an ontological source different from the geometry-led approach, and provides a computable adjacent example for the topological-closure mechanism candidates listed in Info-4, compatible rather than advancing. This paper does not resolve the information paradox, does not claim to replace any existing approach, and offers no direct empirical prediction; it offers only a computable line of thought for the consideration of colleagues. Subsequent work will generalize toward Kerr, the ringdown, and larger sizes.


Appendix A Proofs of the Frozen Ceiling and Related Quantities

A.1 The stabilizer entropy formula

Let the stabilizer space of a pure stabilizer state be $\mathcal S\subset\mathbb F_2^{2n}$, $\dim\mathcal S=n$. Let $\pi_A:\mathcal S\to\mathbb F_2^{2|A|}$ be the projection onto the $X/Z$ columns of $A$; then $\operatorname{rank}\pi_A=\operatorname{rank}_{\mathbb F_2}(G|_A)$. The kernel $\ker\pi_A$ is precisely the stabilizer subgroup supported entirely on $A^c$, so $\dim\mathcal S_{A^c}=n-\operatorname{rank}(G|_A)$. The entropy of the stabilizer state on the subregion $A^c$ is $S(A^c)=|A^c|-\dim\mathcal S_{A^c}$; substituting, $S(A^c)=(n-|A|)-[n-\operatorname{rank}(G|_A)]=\operatorname{rank}(G|_A)-|A|$. The global state being pure, $S(A)=S(A^c)$, which is the formula used. Its non-negativity, upper bound, and subadditivity follow from the general properties of the von Neumann entropy. $\blacksquare$

A.2 The Bell-transfer criterion of $I=2$

Let $A=\mathrm{Ref}_k$, $B=R_{[0,b)}$, $C=(AB)^c$. The global state being pure, $I(A:B)+I(A:C)=2S(A)$. In this model $S(A)=1$, so $I(A:B)=2\iff I(A:C)=0$. And the quantum mutual information is zero iff $\rho_{AC}=\rho_A\otimes\rho_C$, so $A$ is completely decoupled from the complement and all purification lies in $B$. And since $A$ is a maximally mixed qubit, there is a two-dimensional logical subsystem $B_1$ within $B$ such that $|\Psi\rangle_{ABC}\simeq|\Phi^+\rangle_{AB_1}\otimes|\chi\rangle_{B_2C}$. For a stabilizer state, this decomposition is realizable by a Clifford transformation internal to $B$. Hence $I=2$ is precisely the threshold of complete recovery rather than partial correlation. $\blacksquare$

A.3 The mathematical properties of the self-sufficient-window search

For fixed $a$, define $b_{\min}(a)=\min\{b\ge\max(a+2,t_e):I_0(a,b)=2\}$. Since $R_{[a,b)}\subset R_{[a,b+1)}$, the data-processing inequality gives $I_0(a,b)$ non-decreasing in $b$, so the bisection search is exact. If $a_1

A.4 The strict frozen ceiling

The global system at step $t$ decomposes as $R_t\sqcup A_t\sqcup F_t\sqcup Q$. All evolution gates being Clifford unitaries, and emission only changing the ledger assignment of a qubit, the global state remains pure, so $S(R_t)=S(A_tF_tQ)$. Applying subadditivity twice: $S(A_tF_tQ)\le S(A_t)+S(F_tQ)\le S(A_t)+S(F_t)+S(Q)$. Since $A_t$ contains $|A_t|$ qubits, $S(A_t)\le|A_t|$; and since $Q$ contains $N_{\rm ref}$ qubits, $S(Q)\le N_{\rm ref}$. So $S(R_t)\le|A_t|+S(F_t)+N_{\rm ref}$. This inequality depends on neither randomness nor a Page assumption, and is strict conditional mathematics within the framework. $\blacksquare$

A.5 Frozen invariance

For fixed $t$, by definition any qubit in $F_t$ has, since completion of the shallow prep, participated in no gate and not been emitted. So all post-prep unitaries may be written $U_t=I_{F_t}\otimes V_{F_t^c}$. If the post-prep state is $\rho^{(0)}$, then $\rho(t)=U_t\rho^{(0)}U_t^\dagger$. Taking the partial trace over $F_t^c$: $\rho_{F_t}(t)=\operatorname{Tr}_{F_t^c}[(I_{F_t}\otimes V)\rho^{(0)}(I_{F_t}\otimes V^\dagger)]=\rho_{F_t}^{(0)}$. So not only is the entropy invariant, the entire reduced density operator is invariant. $\blacksquare$

A.6 The cut bound of finite preparation depth

Before the shallow prep, the system is a tensor product of product qubits and finitely many Bell pairs. So the initial entropy of any lattice subregion $F$ equals the number of seed Bell pairs crossing that cut: $S_{\rm seed}(F)=B(F)$. Consider a two-qubit gate crossing $F\mid F^c$. Let it act on qubit $x$ on the $F$ side, and write $F=F'\cup\{x\}$. The gate does not change $\rho_{F'}$. Before and after the gate, the Araki–Lieb inequality [11] gives $|S(F)-S(F')|\le1$. So a single crossing two-qubit gate changes $S(F)$ by at most $2$ bits. A gate lying entirely within $F$ or $F^c$ does not change the cut entropy. Each preparation round applies at most one gate per non-remainder bond, so the total number of crossing gates does not exceed $d_{\rm prep}\,|\partial_E F|$. Hence $S_0(F)\le B(F)+2d_{\rm prep}|\partial_E F|$. For the present seed state, $B(F)\le N_{\rm ref}+1$. $\blacksquare$

A.7 Why partial-trace entropy increase at thaw does not break the area order

As the dynamics proceed, the not-yet-touched frozen set shrinks monotonically: $F_{t+1}\subseteq F_t$. Let the part thawed or emitted out be $D_t=F_t\setminus F_{t+1}$; then $\rho^{(0)}_{F_{t+1}}=\operatorname{Tr}_{D_t}\rho^{(0)}_{F_t}$. The partial trace may indeed increase the entropy, so one cannot in general assert $S(F_{t+1})\le S(F_t)$. Nor is that monotonicity needed here. The finite-depth cut bound holds independently for the new region $F_{t+1}$: $S(F_{t+1})\le B(F_{t+1})+2d_{\rm prep}|\partial_E F_{t+1}|$. If the new boundary at all plateau times satisfies $|\partial_E F_t|\le\beta W$, then whether or not some partial trace increases the entropy, $S(F_t)\le N_{\rm ref}+1+2d_{\rm prep}\beta W=O(W)$. So the reason the thaw does not break the area order is not that the partial trace cannot increase the entropy, but that each new frozen region after a thaw is again constrained by the same finite-depth min-cut bound. This is precisely a computable stabilizer instance of local gluing yielding only a min-cut upper bound. Its strict part is the cut bound; that the boundary complexity of the emergent-local arm stays $\beta=O(1)$ within the regime considered is a structural condition of the model, supported jointly by the local rule and the numerical collapse, not an unconditional Hilbert-space theorem. $\blacksquare$

A.8 The volume baseline of the control side

In the control all non-remainder bonds are open, and the post-prep circuit depth grows with evaporation time, so the finite $d_{\rm prep}$ no longer constrains the global entanglement of the frozen interior. The Hilbert-space dimension of the half prefix gives the strict upper bound $S_{\rm half}\le h=M_0/2-1$. Page-type typicality says a typical scrambler should saturate this bound within $O(1)$ corrections. It must be reiterated: the control of this paper is a local Clifford circuit varying with time, not uniform Clifford sampling; so the near-saturation is a compatible phenomenon of Page-type typicality and the numerical baseline of the present control, not a per-sample consequence of Page's theorem for this circuit. The cell medians of the present control data are exactly $287$, $511$, $799=M_0/2-1$, verifying that the baseline operates correctly, not a new finding of this paper. $\blacksquare$


Table 2 Preregistered Criteria and Final Judgment

Criterion Identity Preregistered threshold Final result Verdict
K0primaryremainder semantic conservation (all runs)$110/110$ cleanPASS
K1primaryCV of three medians of $S_{\rm plat}/W$ $<0.2$ and control half $\ge0.9\,M_0/2$CV $=0.0151$PASS
K2primarydepth ladder monotone $\ge95\%$ per size$15/15$ per sizePASS
K3supportingexit-spread and rise-width both non-increasing in $W$rise-width non-monotoneFAIL
K4primary$\widehat\omega_{\rm ctrl}/(M_0/2)$ median $\in[0.95,1.15]$$1.000$ (three sizes)PASS
K5supportingtwo-sided bandall sizes in bandPASS
G1primary$\widehat\omega/S_{\rm plat}$ median $\in[0.9,1.5]$ and cross-$W$ range $\le0.2$range $0.165$PASS
G2primarythree medians strictly increasing in $a_0$$98.5<130<151$PASS

Note: the band $[0.9,1.5]$ and RANGE_MAX $0.2$ of G1 are the preregistered hardcoded fallback, applicable only to the $a_0=2$ arm. Protocol-invalid runs are excluded from the judgment; the rule is in §3.7.


Commitment Grading

The statements of this paper are graded in four tiers by the strength of commitment.

T1-math (strict mathematics within the stabilizer framework): the definition and monotonicity of $p_{\rm open}$; $S(A)=\operatorname{rank}_{\mathbb F_2}(G|_A)-|A|$ and its properties; the complete-Bell-purification criterion of $I=2$; the correctness of the bisection for $t_{\rm exit}$ and $b_{\min}$; the additive $+3$ bound for $\widehat\omega$ within the registered search band; the first inequality of the frozen ceiling $S(R)\le|A|+S(F)+N_{\rm ref}$; frozen invariance $\rho_{F_t}(t)=\rho^{(0)}_{F_t}$; the finite-depth cut bound $S_0(F)\le B(F)+2d_{\rm prep}|\partial_E F|$; the dimensional count $M_0/2-1$ of the control half prefix.

T1-data (facts of the final-round execution): the $110/110$ semantic conservation of K0; the three-median CV $=0.0151$ of K1; the $15/15$ depth ladder per size of K2; the median $1.000$ of K4; the three medians $1.229/1.146/1.311$ and range $0.165$ of G1; the $98.5<130<151$ of G2; the monotone sd and non-monotone rise-width of K3. These are facts of the final-round data, not mathematical theorems.

T2-structure (model-structural readings or conditional structural conclusions): $|A_t|,|\partial_E F_t|=O(W)$ in the plateau interval of the emergent-local arm; hence the area-level scaling $S_{\rm plat}=O(W)$; the self-sufficient window controlled by the same area-level skin capacity; the divergence between frozen area level and control volume level; $c=\widehat\omega/S_{\rm plat}$ a fluctuating structural quantity, not a precise constant.

T3-extrapolation (still beyond the boundary): a universal asymptotic area law as $W\to\infty$ and its precise exponent; a universal $\kappa$ independent of $a_0,w$; the global strict equality $\widehat\omega=\omega^\star$; a precise $c_{\rm th}$; the dynamical dictionary from this stabilizer toy to real black holes, the Hawking spectrum, the island, or the GW waveform.


Data and Code Availability

The SHA-256 of the production manifest ($110$ rows) and the judgment verdict, together with the SHA-256 of the engine, simulator, judge, driver, preregistered ontology, spec, and bond enumeration, and the identifier of the frozen environment, are archived with the paper. The judge is of zero-trust design: anyone holding the same judge code and the same manifest reproduces the same judgment. The final round passed replay concordance across two implementations and an independent re-judgment from the original manifest by an independent implementation with its own logic. The full record of the hardening rounds is in the supplementary material.

The SHA-256 of the five-chain and related hashes are as follows.

manifest: 7bcf0b41f13b6966b1f38d0fec2f98822ef53ec4c738eb75ab98158e033b62e7 verdict: 2588b8226ac82714c54b86849934719a884566dffdd202b972aa0ce4ec0bd57e engine: 0936d1d8819a3beae109a812c9de61a63a0d4ac28296843f04f8caa18382ba1a sim: 3ffa70c973021299996891e0720c84a92a83767777a40410004a1898a02eaf9e judge: c31634dbaf9f15a8e962e0df92dd0362f39499121c11c2c3631d8841ebae5557 driver: 7b2de1b73e6f268c4aa49bd5b6989061537bcc2127d6d596e4bf18441dd8c02f prereg: 1fd7e12c4f79e66256cd0708aaa4aa74ee400744cd111cce5c8661adc4235b97 spec: d71c3a33c3a126b15680162acc5dc0f65b483017ce5fd48683532228312dc0d4

The frozen environment is Python 3.12.3 / NumPy 2.4.4 / x86_64 (scipy-openblas 0.3.31.188.0).


Figure Captions (Figures 1–5 are separate files, uploaded with the paper)

Figure 1 (fig1_schematic) Model schematic: $W\times W$ cylinder, frozen interior $F_t$ (untouched after prep, radial depth labels kept), active skin $A_t$ (closure-addressable layer), the emitted radiation sequence $R$ (subsystem reclassification), the deep/mid/shallow diaries, and the remainder cell $\varepsilon\equiv1$; the arrow on the right indicates the emission direction, and the left and right edges are the periodic boundary of the cylinder. The angular positions of the diaries, the thickness of the active skin, and the position of the remainder cell on the periodic circumference are schematic only, not drawn to production coordinates.

Figure 2 (fig2_entropy_curves) Stepwise radiation entropy $S(R_{[0,t)})$ against emission fraction $t/n_E$, real data (seed 320), two sizes $W=24$ and $W=32$. The control arm (red) shows a symmetric Page curve, its half-stage peak reaching the volume line $M_0/2-1$ (dotted) before turning over; the frozen arm (blue) rises to the middle stage and turns to an area-level plateau ($W24\approx101$, $W32\approx142$), the plateau height rising with $W$, indicating $O(W)$ scaling. Both arms at the end ($t/n_E\to1$) turn over to a $4$-bit endpoint fixed by the remainder cell and the three Ref qubits; this model finally emits $M_0-1$ lattice qubits, with the remainder cell and the three Ref qubits left in the complement, whose reduced state is unchanged by the lattice-side evolution after the initial Bell pairing, so $S(R_{[0,n_E)})=4$ bits and not strictly zero. Relative to the area-level or volume-level main scale, this $4$-bit endpoint lies approximately on the zero line in the figure. This is a boundary effect as the finite-system radiation prefix approaches all emittable lattice qubits; the key of the frozen lies in the mid-stage plateau, not in the end turnover.

Figure 3 (fig3_collapse) Left: the $S_{\rm plat}/W$ of the frozen across three sizes (diamonds are medians, scatter is per-seed), the coefficient of variation of the three medians being $0.0151$, indicating area-level collapse. Right: the $S_{\rm half}/(M_0/2)$ of the control across three sizes lies near $1$ (i.e. the $M_0/2-1$ volume line).

Figure 4 (fig4_selfwindow) The registered self-sufficient-window ratio $\widehat\omega/S_{\rm plat}$ of the frozen across three sizes (blue diamonds are medians: $1.229$, $1.146$, $1.311$, scatter is per-seed), all within the preregistered band $[0.9,1.5]$ (light blue); individual single seeds cross the upper edge, indicating $c$ is a fluctuating quantity and the criterion looks at the cell median, not the single seed. The $\widehat\omega_{\rm ctrl}/(M_0/2)$ of the control (red squares) is $1.000$ across three sizes.

Figure 5 (fig5_ladder_k3) Left: the normalized exit times $\tau_{\rm exit}$ of the deep/mid/shallow diaries of the frozen across three sizes, the deep latest and the shallow earliest, a $15/15$ ladder per size. Right: K3 (supporting) on twin axes, the sd of the deep-diary exit-spread (blue, $0.0525/0.0289/0.0219$ monotonically decreasing) and the normalized rise-width (red, $0.0730/0.0381/0.0563$, with a reversal rebound at $W40$); the front sharpening obtains only partial support.

Table 1 (operational objects and the SAE ontological dictionary) is in §2.B, and Table 2 (all preregistered criteria, thresholds, final values, and judgments) is in the body; both tables are included in this paper.


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Acknowledgments

The research of this paper adopted a multi-AI collaborative review method at the various stages of drafting, through multiple rounds of divergent review, adversarial cross-checking, and independent re-judgment; the models used include ChatGPT, Claude, Gemini, and Grok. For all claims, arguments, and possible errors in the content, the responsibility lies entirely with the author.