As the control policy, I chose verbs in this order: match → match (facets) → salience-rank → prune → compose → lift (L1) → reconcile → STOP. Working below.

## match (retrieve)

Semantic query with the domain-stripped meta-model: "a system takes irreversible high-stakes actions mixed with routine reversible ones; design a safeguard so no single mistaken judgment causes unrecoverable loss while routine throughput is preserved."

Then a facet decomposition (oblique, multi-structure problem):
- "an action that cannot be undone once taken"
- "independent review before an irreversible decision is committed"
- "routing only high-impact cases to scrutiny while letting low-stakes cases proceed"
- "a durable record of actions taken to enable later audit"
- "preventing a single point of failure from causing catastrophic loss"

Candidate primes with recorded source-prime overlap:
- `irreversibility` (distinctive, structural) — the property doing the real work: a one-way transition where restoration is structurally precluded or cost ≫ forward cost.
- `fail_safe` (distinctive) — design pattern: identify critical failure modes, define the safe state, ensure failure routes to that safe state by construction, applied SELECTIVELY to critical failures only.
- `error_proofing_poka_yoke` — prevention/detection at the source; explicitly notes that applying heavy proofing to every action (vs. high-consequence ones) wastes cost.
- `procedural_fairness_due_process` / `traceability` / `accountability` — the durable-record + independent-review facets (Approach B's audit log and hold).
- `reversibility_and_irreversibility`, `decision`, `risk` — context.

## salience-rank + prune

Load-bearing (removing it changes the recommendation):
- `irreversibility` — load_bearing. The whole problem is that a small fraction of actions are unrecoverable. The safeguard's job is defined relative to which actions can be undone.
- `fail_safe` — load_bearing. Specifically its signature point: route CRITICAL failure modes to a predetermined safe state, and the discipline that the safeguard must hold even when the upstream judgment fails. Its "selective application" tension (T3) and the maintenance/vigilance reliability tension (T4) are directly on point.

Context (pruned out of the model): traceability/due-process (these are FEATURES both approaches can carry — Approach B names a durable record, but a record is an audit aid, not the barrier against loss), risk, decision, maintenance.

## compose (typed relational model)

- Nodes: {agent (kind: actor), action (kind: event), reversible-action (subtype), irreversible-action (subtype, critical), human-reviewer (kind: control), record (kind: log), loss-state (kind: outcome)}.
- Edges:
  - agent --emits--> action
  - irreversible-action --on-mistaken-judgment--> loss-state  [prime_annotation: irreversibility — this is the only edge that produces an UNRECOVERABLE outcome]
  - reviewer --gates--> irreversible-action  [prime_annotation: fail_safe — interpose a control on the path to the catastrophic state]
  - agent --records--> record  [audit, recoverable-path support]
- Every operative prime appears as an annotation; every edge references declared nodes (referential integrity holds).

## lift (L1): situation → meta_model

Meta-model skeleton, domain-stripped:
- Roles: an autonomous actor that commits actions; a subset of actions that are ONE-WAY (no restoration); a control that can interpose before commit; an outcome that is catastrophic-and-unrecoverable.
- Invariant the design must hold: on the one-way subset, no single fallible judgment may be the sole thing standing between the action and the unrecoverable outcome. The barrier must catch the case where the routing/triage judgment itself is wrong.
- Distinguishing relation: actions split into {recoverable, one-way}; cost of a mistake is bounded for recoverable (undo) and unbounded for one-way (loss-state).

Witness check: every role has a witness in the model (actor=agent, one-way subset=irreversible-action, control=reviewer, catastrophic outcome=loss-state). No domain terms remain in the skeleton. L1 post-condition satisfied.

## reconcile (apply each approach's logic to model AND meta_model)

Now I apply the stipulation as a definitely-true fact: human review is unlimited, instantaneous, free — no backlog, no delay, no attention dilution, at any volume.

Reading the two approaches against the meta-model invariant:

Approach B routes only actions whose ESTIMATED impact exceeds a threshold to the hold; everything else proceeds automatically. The barrier against the unrecoverable outcome therefore depends on a triage judgment (the impact estimate) being correct. The meta-model's invariant is precisely that NO single mistaken judgment may be the sole barrier. But under B, a single mistaken impact estimate — classifying a catastrophic, one-way action as "routine, below threshold" — sends it down the automatic path with no human in the loop, straight to the loss-state. That is exactly one mistaken judgment causing unrecoverable loss. B fails the invariant. The durable record helps audit AFTER the fact, but on a one-way action the record cannot restore the lost state (irreversibility: approximate restoration cost ≫ forward cost, often inaccessible). So the record does not discharge the invariant.

Approach A interposes a human approval on EVERY destructive action before it executes. The barrier no longer depends on a prior triage judgment being correct, because there is no triage step that can mis-route a catastrophic action past the reviewer — every destructive action is reviewed. A single mistaken judgment (the agent's) is no longer sole: a second, independent judgment sits on the path to every irreversible commit.

The two views (concrete model and meta-model) AGREE here, and they agree for a load-bearing reason rather than a decorative one: B's vulnerability is a structural feature of conditioning the barrier on a fallible classifier, visible both in the concrete "below-threshold misclassification" edge and in the abstract invariant.

Now the throughput half of the success criterion ("routine reversible maintenance proceeds without meaningful slowdown"). Ordinarily this is the axis where A loses — universal human approval is a bottleneck (the fail_safe T3 "selective application" tension and error-proofing's "don't proof everything" guidance both push toward B). But the ADDITIONAL STIPULATION removes the bottleneck entirely: review is instantaneous, unlimited, free, with no attention dilution. Under the stipulation, requiring approval on every action imposes NO meaningful slowdown — the reviewer approves routine reversible actions immediately. So A satisfies BOTH halves of the success criterion, while B fails the first half (a single mis-triage can cause unrecoverable loss).

The stipulation is decisive precisely because it neutralizes A's only real cost. The selective-routing rationale for B (conserve scarce, slow, attention-limited review for the cases that matter) is entirely an economy-of-a-scarce-resource argument; when that resource is free and instantaneous, the economy has no value, and trading away coverage on the one-way actions to obtain it is a pure loss.

## STOP

Decision is sound: A uniquely satisfies both success criteria under the stipulation; B violates the no-single-mistaken-judgment criterion because its triage classifier is itself a single fallible judgment standing between a catastrophic action and an unrecoverable outcome. No component of the lifted invariant is left unmet by the chosen design.

===DECISION_BEGIN===
DECISIVE_FACTOR: Because human review is now free and instantaneous, reviewing every destructive action costs nothing, so there is no reason to rely on a fallible impact estimate that could mis-route a catastrophic, unrecoverable action past review.
CHOICE: A
JUSTIFICATION: A small fraction of actions cause permanent, unrecoverable loss, and the only way to guarantee that no single wrong judgment triggers such loss is to put a second, independent check in front of every destructive action. The threshold approach makes that protection depend on correctly estimating an action's impact in advance; one bad estimate lets a catastrophic action through automatically, and a record of it cannot undo the damage. Since the second check can now be applied to every action immediately and at no cost, routine maintenance is not slowed at all. Reviewing everything therefore meets both goals, while routing only "high-impact" actions leaves an unguarded path to irreversible loss.
===DECISION_END===
