A ratio of \(1\) is the operational boundary. The reported headline \(\lambda_f^*\) is the longest continuously passing soft-margin prefix from \(\lambda=0\); a later re-entry cannot extend it. Higher \(\lambda_f^*\) and \(\mathrm{AUDC}^{\mathrm{norm}}_f\) indicate greater capacity. The statistical unit is one task-family stress cell, aggregated from eligible episode–seed paths.
UNIT OF ANALYSIS
Family stress boundary
Eligible episode–seed curves form task-family stress cells; the complete family curve determines \(M_f(\lambda)\), \(\lambda_f^*\), and \(\mathrm{AUDC}_f\).
Five channels
PC: task completion; Q: proposition satisfaction; Safety: safety burden; Rebound: recovery cost; Stability: formal perturbation sensitivity. The two weakest channels determine the soft margin, and the weakest channel determines the hard margin.
ALL TEN EPISODES
Eligible episode–seed paths
Official paths require six shared stress rows; strict paths also require valid critic-lifecycle and reward-shaper evidence at all six levels.
| Family | Episode | Seed 0 | Seed 1 | Seed 2 | Official | Strict |
|---|---|---|---|---|---|---|
| Placement | 75 | Strict | Strict | Excluded | 2/3 | 2/3 |
| 78 | Strict | Official only | Strict | 3/3 | 2/3 | |
| 98 | Strict | Strict | Strict | 3/3 | 3/3 | |
| Mixed | 239 | Excluded | Strict | Strict | 2/3 | 2/3 |
| 258 | Excluded | Strict | Excluded | 1/3 | 1/3 | |
| 290 | Strict | Excluded | Strict | 2/3 | 2/3 | |
| 304 | Excluded | Excluded | Excluded | 0/3 | 0/3 | |
| Spatial | 131 | Excluded | Excluded | Excluded | 0/3 | 0/3 |
| 144 | Excluded | Excluded | Strict | 1/3 | 1/3 | |
| 174 | Excluded | Excluded | Excluded | 0/3 | 0/3 |
Denominator definition: Among 30 candidate paths, official shared-complete=14 (Placement 8 + Mixed 5 + Spatial 1) and strict-complete=13. The single complete Spatial path remains in the support audit; its clean reference has n=1<min_samples=2, so its family cells remain N/A. Operative support for estimable families is therefore 13 official paths and 12 strict paths.
OFFICIAL BOUNDARY
First stress boundary
Placement and Mixed first fail at \(\lambda=.2\); Spatial remains N/A because its clean reference has \(n=1<2\).
AUDC=0.4668; official 8/9, strict 7/9, across 3/3 episodes.
AUDC=0.5027; official/strict 5/12, across 3/4 episodes.
1/9 path; the clean-reference min_samples criterion is unmet.
Both estimable families cross the boundary at the smallest positive stress.
CASE STUDY
Placement boundary case
Placement combines the family-level boundary estimate with contributing execution traces across Episodes 75, 78, and 98.
IMAGEGEN · FAMILY-BOUNDARY CONCEPT · CONCEPTUAL, NON-NUMERICALPLACEMENT · MULTI-ROLLOUT ESTIMATOR
Stability-limited first cliff
Placement covers eight official-complete paths across Episodes 75, 78, and 98. At λ=0, the soft margin is +0.0556. At λ=.2, rPC=rQ=1.111, while rstab=9.12×10−7 and rrec=0.727 reduce the soft margin to −0.6367 and the hard margin to approximately −1.
The ImageGen panel communicates the conceptual geometry of five channels sharing a boundary while the weakest channel contracts early. Numerical claims derive from GE cells and support CSV files.
ENGLISH ASPECT VIDEO · EVIDENCE-ALIGNED
Episode 78 at the boundary
This trace-driven reconstruction compares Episode 78 / seed 1 clean and λ=.2 contributing rollouts. Msoft, λ*, and normalized AUDC remain Placement-family summaries (n=8 per cell; 8/9 complete paths), and λ*=0 is interpreted as a provisional threshold-calibration diagnostic.
TRACE-LEVEL CASE STUDY
Boundary and trajectory evidence
The trajectory browser applies two fixed comparisons to all 180 candidate runs. The longitudinal analysis follows Episode 78 / seed 1 across six stress levels, and the cross-sectional analysis holds seed 1 / λ=1.0 constant across episodes. GE capacity remains a task-family aggregate.
GRACEFUL EXTENSIBILITY · TWO-LEVEL EVIDENCE
From cells to planning nodes
Each panel reports the family-level margin alongside single-run simulation fields. Trajectories explain channel mechanisms, and capacity is aggregated from the complete eligible stress curves for that family.
LONGITUDINAL COMPARISON
Episode 78 stress trajectories
Six independent rollouts hold episode, seed, task contract, Planner, and Judge settings fixed.
- Aspect
- GE · family stress-response
- Primary trajectory
- Episode 78 · placement_only
- Controlled identity
- seed 1 · GPT-5.1 Judge
- Family support
- 8/9 official · 7/9 strict
Clean: API repair
- Initial parameters omitted
The planner directs toy food and the toy fire truck to chest_of_drawers_37; both Rearrange calls return the five-parameter API requirement.
- Objects and target furniture resolved
Thought summary: explore bedroom_1, verify the object instances, and select chest_of_drawers_36 as the target.
- Five-parameter Rearrange executes
Agent 0 places toy_food_1 successfully while Agent 1 continues the parallel transfer of toy_fire_truck_0.
- All propositions satisfied
Both objects are on chest_of_drawers_36, with task completion=1.0.
First-cliff repair
- Two incomplete Rearrange calls
The observation returns the five-parameter template while completion remains 0.
- Object resolution and second API repair
Thought summary: after identifying toy_food_1 and toy_fire_truck_0, add the spatial relation and constraint parameters.
- First object transferred
Agent 0 completes the five-argument Rearrange, placing toy_fire_truck_0 on the target furniture.
- Navigation target and placement distance unmet
Agent 1 first reports an inaccessible target; Place then fails because of distance or occlusion, prompting an Explore → Navigate → Place recovery.
- Terminal state satisfied
Place succeeds for the second object and completion rises to 1.0.
High-sensitivity short rollout
- Exploration begins from an empty object list
The planner assigns both agents to explore bedroom_1.
- Furniture navigation target rejected
Agent 1 cannot resolve a reachable navigation target for chest_of_drawers_36.
- Held-object state triggers reassignment
Agent 0 completes toy_food_1; the planner detects that Agent 1 holds toy_fire_truck_0 and switches to Navigate and Place.
- Placement completed
Completion reaches 1.0. This rollout has β=1.746, the highest of the six Ep78 / seed 1 points.
Clean execution shape reproduced after specification repair
- Object visibility established
The run first explores bedroom_1 and then directs both targets to chest_of_drawers_36.
- Two-parameter Rearrange rejected
The observation supplies the complete API template, and the planner immediately adds relation and constraint fields.
- Parallel repaired actions take effect
Agent 0 first reports successful execution while Agent 1 remains in progress.
- Both objects completed
The execution shape closely matches clean, while the current family cell remains constrained by the Stability ratio.
From empty action assignment to the shortest successful rollout
- Initial plan remains at Wait
Both agents report “No actions were assigned,” and task progress remains 0.
- Explicit navigation and five-parameter repair
The planner activates bedroom navigation and then submits complete Rearrange parameters in parallel.
- First object completed
Agent 0 reports success while Agent 1 continues the second object.
- Shortest completion path
This level has the fewest simulation steps and Crec=8.968; the family margin remains constrained by the aggregated channels.
Stable completion under high stress with persistent boundary violation
- Object index recovered
The object list is initially empty, and the planner begins by exploring bedroom_1.
- Two simplified Rearrange calls rejected
The system returns explicit requirements for spatial relation, furniture, and constraint fields.
- Parallel execution after specification repair
Thought summary: set relation to on and explicitly fill the spatial constraint and reference object with None.
- Completion and termination
Completion reaches 1.0 and simulation steps match clean; the Placement-family λ* remains 0.
CROSS-SECTIONAL COMPARISON
Fixed-stress episode comparison
Seven episodes share seed 1 and \(\lambda=1\); Episode 304 is the outcome-associated negative control.
Concise parameter repair after perception refresh
- Object index refreshed
Thought summary: use a perception scan to locate stuffed_toy_0 and toy_vehicle_1.
- Simplified Rearrange fails
The target couch_23 is resolved, while the call omits the spatial relation and constraint fields.
- Both objects placed
Complete Rearrange calls advance completion from 0 to .5 and then to 1.0.
Position of the longitudinal anchor at fixed λ
- Exploration from an empty object list
The run locates two toy objects and the target chest_of_drawers_36.
- Spatial parameters completed
The call is converted from a two-parameter form into a five-argument Rearrange.
- Completion and termination
Both objects satisfy their placement propositions.
Three-object placement extends the simulation horizon
- Objects initially absent
The planner cannot find the laptop, monitor stand, or credit card in the object list; navigation and exploration update the state.
- First object placed
After the Rearrange parameters are completed, laptop_0 reaches couch_11.
- All three objects completed
laptop_0, monitor_stand_1, and credit_card_2 are all placed on couch_11.
High recovery burden in multi-goal mixed-temporal execution
- Two cross-room goal groups decomposed
The task requires transferring three credit cards while placing a gaming console and canister on a bedroom bed.
- Insufficient pick distance
Pick[credit_card_0] reports “not close enough”; the planner moves closer to chair_20 and retries.
- First card placed
After Navigate and Place succeed, execution proceeds to the remaining cards and bedroom objects.
- Six propositions completed
Terminal relations are satisfied for the three cards, console, and canister.
Two-stage transfer of a plant and saucer
- Object instances and parameters unresolved
The initial simplified Rearrange calls for plant_0 / saucer_0 are rejected.
- Object instances corrected
Exploration identifies plant_saucer_1 and plant_container_0, which are first transferred to living-room table_10.
- Transition from living room to kitchen counter
The saucer is retained as the reference object to establish the next_to relation.
- Two-stage task completed
Both objects are on counter_19 and adjacent to one another.
Long execution trace with missing paired β
- Initial object name misalignment
Simplified calls for apple_0 and lamp_0 are rejected; exploration corrects the lamp instance to lamp_2.
- Intermediate office-table state completed
apple_0 and lamp_2 reach table_36, while toy_animal_1 remains on bed_16.
- Transfer to the living-room bench
Alternating Pick, Navigate, and Place actions establish adjacency between the apple and lamp.
- Terminal propositions completed
Both transferred objects are on bench_10, and the toy animal remains on the bedroom bed.
Planner termination claim diverges from task outcome
- Simplified plant-transfer call fails
Rearrange[plant_0, bench_10] omits the spatial relation and object-instance information.
- First-stage plant transfer succeeds
The instance is corrected to plant_container_0 and placed on table_30 after the on relation is supplied.
- Cushion and toy vehicle continue
The planner records execution of three subgoals, while the Judge retains one unsatisfied proposition.
- Termination at completion .75
The planner trace declares completion with task_state_success=0; Crec and paired β are both N/A.
Complete indices: Download the 180-run index, 3115-node planning-event index, and case-selection manifest. Candidate screening covers all 10 episodes; Thought summaries condense only planner rationale explicitly recorded in the trace.
CHANNEL FORENSICS
Origin of \(\lambda^*=0\)
Clean \(\beta=0\) sets \(\tau_{\mathrm{stab}}=0\), inducing the first positive-stress Stability cliff under the current calibration.
For \(\lambda>0\) and \(\beta(\lambda)>0\), \(r_{\mathrm{stab}}\) contracts to approximately \(10^{-6}\)–\(10^{-5}\), yielding \(M_f^{\mathrm{hard}}\approx-1\). The observed \(\lambda^*=0\) is therefore a threshold-calibration diagnostic; estimating system perturbation capacity requires an independently calibrated Stability threshold.
Family-specific secondary bottlenecks
Placement is principally constrained by Rebound at λ=.2/.6/.8 and by Safety at λ=.4/1.0. For Mixed at λ=.6, Rebound ratio=0.500 yields the deepest soft margin, −0.750. At other stress levels, the second bottleneck shifts among Safety, Rebound, and PC/Q.
MECHANISM-RICH FAMILY CONTRAST
Mixed-family comparison
Mixed \(\lambda^*=0\) uses 5/12 official paths across Episodes 239, 258, and 290; Episode 304 remains an excluded negative control.
Mixed official curve
At λ=0, the soft margin is +0.0556; at λ=.2 it declines to −0.4444. At λ=.6, rrec=0.500 and a near-zero rstab produce the curve’s deepest soft margin, −0.7501. AUDC=0.5027 indicates slightly greater integrated retention over the current support set than Placement; both families retain λ*=0.
Episode 304 negative control
task_state_success=0/18; mean completion=0.6667, with 16/18 runs at 0.75 and 2/18 at 0; Crec valid=0/18. Its exclusion from the Mixed estimator demonstrates the support-selection dependence of PC/Q=1.111 in complete-pair cells.
SUPPORTING TRAJECTORIES
Prespecified mechanism excerpts
Three strict-complete successful paths explain mechanisms while each family estimate retains every eligible path.
PRIMARY FAMILY MECHANISM
Placement · Ep78 / seed 0
λ=.2: Crec=25.454, β=1.408, unsafe=.0207, 1252 steps, success. Explore resolves the target and a two-agent Rearrange repair follows; terminal success co-occurs with a near-zero Stability ratio.
MIXED FIRST-CLIFF EXCERPT
Mixed · Ep239 / seed 2
λ=.2: Crec=18.113, β=1.151, unsafe=.0219, 2689 steps, success. A two-parameter Rearrange error is repaired; `next_to,None` then fails, followed by completion with a reference object.
MIXED REBOUND BOTTLENECK
Mixed · Ep258 / seed 1
λ=.6: Crec=75.256, β=.305, unsafe=.0253, 1702 steps, success. After repeated use of invalid `next_to,None`, the saucer is placed first and then used as the reference for the plant.
| Report role | Path / cell | Eligibility | Quantitative anchor | Trace question | Estimator status |
|---|---|---|---|---|---|
| Placement first-cliff mechanism | Ep78 / seed 0 / λ=.2 | Strict complete; success=1 | β=1.408; Crec=25.454 | How does success co-occur with the Stability cliff after parameter repair? | Excerpt only |
| Mixed first-cliff contrast | Ep239 / seed 2 / λ=.2 | Strict complete; success=1 | β=1.151; Crec=18.113 | Does the same first-cliff cell contain an auditable error–repair sequence? | Excerpt only |
| Mixed Rebound bottleneck | Ep258 / seed 1 / λ=.6 | Strict complete; success=1 | family rrec=0.500; Crec=75.256 | How does the second Rebound bottleneck accumulate across actions? | Excerpt only |
The selection table can be verified against the case-selection audit CSV, trajectory-source CSV, and official family-cells CSV. Trajectory excerpts address how a channel mechanism can arise; family GE remains jointly estimated from all eligible episode×seed curves in the corresponding task family.
REPORTED FAMILY CELLS · ROUNDED
Channel ratios and margins
Ratios use the clean family reference; retained precision resolves \(M_f^{\mathrm{hard}}\) from \(-1\), and invalid Spatial placeholders are omitted.
Placement
| λ | PC | Q | Safety | Rebound | Stability | M soft | M hard |
|---|---|---|---|---|---|---|---|
| 0 | 1.111 | 1.111 | 1.250 | 1.250 | 1.000 | +0.0556 | 0 |
| .2 | 1.111 | 1.111 | .903 | .727 | 9.12e−7 | −.6367 | −.99999909 |
| .4 | 1.111 | 1.111 | .800 | .857 | 5.97e−7 | −.6002 | −.99999940 |
| .6 | 1.111 | 1.111 | 1.535 | .771 | 2.95e−6 | −.6144 | −.99999705 |
| .8 | 1.111 | 1.111 | 1.310 | .772 | 1.55e−6 | −.6140 | −.99999845 |
| 1 | 1.111 | 1.111 | 1.086 | 1.321 | 4.45e−6 | −.4571 | −.99999555 |
ROBUSTNESS & LIMITATIONS
Inference tiers
Lifecycle-strict analysis narrows support while preserving the original rollouts, exclusions, and qualitative boundary test.
Shared-complete=14; operative curves for estimable families=13. Placement AUDC=.4668 and λ*=0; Mixed AUDC=.5027 and λ*=0.
Shared-complete=13; operative curves for estimable families=12. Placement AUDC=.4763 and λ*=0, preserving the qualitative conclusion.
In this diagnostic, Mixed λ*=.2 and Placement remains 0. The preregistered formal GE retains the complete five-channel definition.
Independent clean–clean replication must estimate a nonzero noise floor; exact capacity can then be recomputed after preregistration of τstab.
Calibrated interpretation: Under the current degenerate threshold induced by clean β=0, formal GE structurally crosses the hard boundary at the first positive-stress cell. This provisional result primarily reflects threshold calibration; physical capacity requires independent calibration.
