## Working (control policy — free verb choice)

**match (search_prime, meta-model).** Domain-stripped query: "a small fraction of actions cause irreversible catastrophic loss while most are routine and reversible; a safeguard must prevent any single mistaken judgment from causing unrecoverable harm without slowing the routine flow." Top structural hits: `irreversibility` (distinctive), `reversibility_and_irreversibility`, `controlled_reentry`/`circuit_breaker` neighborhood, `risk`, `resilience`.

**match (search_by_facets, oblique).** Decomposed into five structural facets: (1) irreversible action after execution, (2) screening high-stakes from routine, (3) independent review before commit, (4) single point of judgment whose error causes total loss, (5) human approval as throughput bottleneck. Per-facet surfaced the load-bearing set:
- Facet 1 → `irreversibility`, `controlled_reentry`
- Facet 2 → `screening` (distinctive, 0.696)
- Facet 4 → `loss_aversion`, `type_i_type_ii_errors`, `risk`
- Facet 5 → `decision_fatigue`, `cognitive_resource_depletion`, `scalability`, `interference_and_contention` — i.e. universal approval is itself a load/contention failure mode.

**salience-rank / prune.** Keep `irreversibility`, `screening`, `circuit_breaker`. Drop `reversibility_horizon`, `bystander_effect`, `self_handicapping`, `adverse_selection` as off-structure. The decisive triad: what makes the harm matter (irreversibility), how to route by stakes (screening), how to interrupt only the dangerous ones (circuit breaker).

**lift (get_prime: irreversibility).** The structural core: a subset of actions has a *privileged direction* — restoration requires a debit that is costly or in-principle inaccessible. Key reasoning move it licenses: irreversibility is a *multiplier on expected-harm*; when downside is unrecoverable you weight the probability of passage far more heavily, and you preserve optionality *before* the one-way step. This is the success criterion's first clause exactly: no single mistaken judgment may cause unrecoverable loss.

**lift (get_prime: screening).** Structural core: an uninformed gate cannot afford to verify every case directly (impractical / prohibitively costly), so it routes by a *type-revealing* threshold and applies costly scrutiny only where it pays. Directly relevant: applying the heavyweight control to *every* action is the rejected baseline ("attempt direct type verification for every applicant — often impractical"). The right design distinguishes high-stakes from routine and spends scrutiny accordingly.

**lift (get_prime: circuit_breaker).** Structural core: monitor a flow, trip on a danger threshold, isolate the fault, hold open until a gated reset; the three tunable parameters are *trip threshold*, *isolation scope*, *reset policy*. This is precisely Approach B's shape: threshold-gated routing of only the dangerous fraction to an independent hold, routine flow proceeds, with a durable record. Tension T5 (a breaker can amputate a limb that would have healed) and T1 (sensitivity vs. availability) are the live design risks — but they bite *Approach A harder*, since A trips on everything.

**compose (typed relational model).**
- Population of actions = {routine-reversible (majority), catastrophic-unrecoverable (small fraction)}.
- Failure to avoid (success clause 1): one mistaken judgment → unrecoverable loss. Only the catastrophic subset can produce this.
- Failure to avoid (success clause 2): routine maintenance meaningfully slowed.
- Control surface = where human/independent review is inserted.

**evaluate-fit (gate against known failure conditions).**

*Approach A — human approves EVERY destructive action.*
- Clause 1 (no single mistake → unrecoverable loss): A places a human gate on the catastrophic subset, so it *covers* the irreversible cases. BUT it floods the reviewer with overwhelmingly routine approvals. By `decision_fatigue` / `cognitive_resource_depletion` / `interference_and_contention`, the rare catastrophic item arrives buried in a high-volume stream of harmless ones — the reviewer rubber-stamps, and the *single mistaken judgment* the criterion forbids becomes *more* likely, not less. The gate exists but its reliability degrades exactly where it matters. (Screening's lesson: verifying every case doesn't scale and corrodes.)
- Clause 2 (routine proceeds without meaningful slowdown): A *fails outright* — every routine reversible action waits on a human. This is a direct violation.

*Approach B — threshold routes only high-impact actions to independent review/hold; routine reversible actions auto-proceed with a durable record.*
- Clause 1: B is a circuit-breaker over a screened population. The irreversible/catastrophic subset is exactly what crosses the threshold and is held for independent review before commit — so no single automated judgment can execute an unrecoverable action unreviewed. The durable record preserves auditability/optionality on the routine ones. Covers clause 1, and concentrates scarce review attention where the stakes are, so the review is *higher quality* than A's flooded one.
- Clause 2: routine reversible actions proceed automatically → satisfied by construction.
- Residual risks (honest accounting): threshold miscalibration could mis-route a catastrophic action as routine (circuit-breaker missed-trip, T1/T4). Mitigation lives in setting the trip on *irreversibility/impact* (not frequency) and biasing toward over-inclusion at the boundary; reversibility of routine actions means a mis-routed *reversible* action is recoverable by definition. The asymmetry of the harm (irreversibility as multiplier) tells us to tune the threshold conservatively — which B's structure permits and A cannot even express (A has one undifferentiated gate).

**reconcile.** A satisfies clause 1 only nominally while certainly violating clause 2 and quietly undermining clause 1 via reviewer overload. B satisfies clause 2 by construction and satisfies clause 1 more *robustly* than A, because impartial review is reserved for the unrecoverable subset where human judgment is actually decision-relevant. The only thing A buys over B is coverage of low-impact destructive actions that are, by stipulation, reversible — paid for with a guaranteed throughput violation and a degraded high-stakes gate. B dominates on both success clauses.

**STOP.** Decision is sound. Choose B.

===DECISION_BEGIN===
DECISIVE_FACTOR: Because the harm that must be prevented lives only in the small unrecoverable subset, scrutiny should be concentrated there — routing only high-impact actions to independent review protects against catastrophic mistakes far more reliably than burying the rare dangerous case in a flood of routine approvals.
CHOICE: B
JUSTIFICATION: The only actions that can cause permanent, unfixable loss are a small minority, so that minority is where careful independent review actually pays off. Sending every routine, undoable action to a human both stalls ordinary work and overloads the reviewer, so the rare dangerous item gets a tired rubber-stamp instead of real attention. Holding only the high-impact actions for review — while letting reversible ones proceed with a complete record — keeps routine maintenance fast and puts the strongest check exactly where an error would be irrecoverable. Set the hold threshold on potential impact and bias it toward catching anything unrecoverable.
===DECISION_END===
