---
slug: post_initiation_failure_arrest
name: Post-Initiation Failure Arrest
one_liner: "A system survives not by preventing local damage from starting but by arresting an already-initiated failure before it propagates to completion, separating damage initiation from damage spread."
type: prime
schema_version: 2
status: density_v2_draft
categories: [structural, physical, biological]
origin_domain: fracture_mechanics
alternate_origin_domains: [reliability_engineering, epidemiology, ecology, systems_safety]
aliases: [propagation_arrest, containment_over_prevention, spread_interruption, damage_confinement, brittle_vs_tough_response]
related: []
solution_archetypes: []
review_flags:
- "OPERATOR-DERIVED (op-05 generalization) — the proposed GENUS of `fracture_toughness` (lift: strip the materials-science frame — crack-tip stress, initiation vs. propagation of a physical crack — to expose the bare pattern of arresting an already-initiated local failure rather than preventing initiation). Discovered in the op-05 remaining-strata sweep 2026-07-03. Tier B candidate (COINAGE RISK — see keep/cut). STATUS: HOLD pending owner keep/cut."
- "Tier-B domain-instance / coinage flag (from data): arresting already-initiated local failure (vs. prevention) genuinely absent from corpus; siblings span grid (circuit breakers halting cascade), immune (containment of an infection focus), and wildfire (firebreaks) domains. Sibling-test passes, but the genus label is a proposer coinage, not an established named structure — treat with skepticism."
- "Created 2026-07-03; STUB ONLY (frontmatter + Core Idea + Notes). SI/SF/similarity are PROPOSER ESTIMATES pending triangulation. Body sections (Structural Signature onward) NOT written."
- "Phase-C action: re-similarity-check vs `fracture_toughness` (the input) and the named siblings, AND vs any existing cascade / containment / robustness / fault-isolation prime; confirm it is a genuine genus (covers the input AND the grid/immune/wildfire siblings) and not a domain instance, a restatement of the input, or an alias of an existing containment/cascade prime; draw a subsumption edge input→candidate + sibling edges at incorporation; sync one_liner to a v1 draft per CLAUDE.md before merge."
substrate_independence:
  composite_substrate_independence: 4
  domain_breadth: 4
  structural_abstraction: 4
  transfer_evidence: 3
  reasoning: 'The bare structure — a system in which local failure has already initiated, and survival turns on whether that failure is arrested before it propagates to global completion, with initiation and spread treated as separable phases — is genuinely domain-neutral and recurs across physical, engineered, biological, and ecological substrates (crack arrest, breaker trip, immune containment, firebreak). That supports domain breadth and structural abstraction around 4. The reason it is not a 5: the pattern rides on a background notion of a propagating disturbance on a connected medium, and the "arrest" is somewhat entangled with adjacent structures already likely in the corpus (cascade / percolation / containment), so its independent identity is less crisp than a Tier-A genus. Transfer evidence is real but the label is a coinage rather than an established cross-field term, so transfer_evidence sits at 3 pending confirmation the siblings are not better filed under an existing prime.'
similarity_to_nearest_existing_prime:
  slug: fracture_toughness
  similarity: 0.62
structural_framed:
  label: structural
  aggregate: 0.24
  criteria: {vocab_travels: 0.3, evaluative_weight: 0.2, institutional_origin: 0.2, human_practice_bound: 0.3, import_vs_recognize: 0.2}
  rationale: 'The pattern is largely structural — it describes a phase separation (initiation vs. propagation) and an arrest condition that carry no domain-specific vocabulary and only a mild evaluative tint (survival is implicitly the good, but the structure itself is value-neutral). It is recognized as the same shape across materials, grids, immune systems, and fire rather than imported as a doctrine. The nonzero criteria reflect a faint bias toward engineered-safety framing (the language of "failure" and "survival") rather than any real institutional binding. Reads structural, with a coinage caveat that lowers confidence rather than the label.'
phase_b_passes_completed: []
---
# Post-Initiation Failure Arrest

## Core Idea

Post-initiation failure arrest is the structural pattern in which *a system's survival depends not on whether local damage starts but on whether, once started, that damage is arrested before it propagates to global completion*. The single constraint stripped from the input `fracture_toughness` is its materials-science frame: the input describes a physical crack, its crack-tip stress field, and the energy balance governing whether that specific crack propagates. This genus keeps the load-bearing separation — *initiation of local failure* versus *spread of that failure* — and drops the requirement that the failure be a mechanical crack in a solid. What remains is any system in which a local defect has already occurred and the design question is spread-arrest, not initiation-prevention.

The load-bearing anatomy has three parts. First, a *separable initiation phase*: local damage can and does occur, and the structure accepts this rather than treating prevention as the only defense. Second, a *propagation dynamic*: once initiated, the failure has a tendency to run — to spread along couplings to neighboring elements until it reaches system-wide completion. Third, an *arrest mechanism*: some feature that halts, blunts, or confines the propagating failure at a boundary, so the local defect stays local. The characteristic payoff is *graceful survival of damage*: a system with strong arrest can be repeatedly damaged and yet never fail globally, decoupling its reliability from the impossible goal of a defect-free state. The characteristic cost and failure mode is *brittleness* — its exact opposite: a system that is hard (resists initiation) but has no arrest runs any initiated failure straight to completion, and such systems fail catastrophically and without warning precisely because all their defense was spent on prevention. The recurring tension is therefore the trade between hardness (raise the initiation threshold) and toughness (raise the arrest capacity), and the structural insight is that beyond a point only the latter buys survivability.

Read as a genus rather than as fracture, the same skeleton recurs across structurally unlike domains. In *power grids*, circuit breakers and protective relays exist to *arrest* a fault that has already occurred — they trip to halt a cascading overload before it propagates across the network, accepting the local fault to save the whole. In *immune defense*, containment of an infection focus (granuloma formation, walling off, localized inflammation) arrests an already-established pathogen locus before it spreads systemically — the body does not prevent every infection but confines the ones that start. In *wildfire management*, firebreaks and controlled burns arrest an already-ignited fire's spread across a landscape — ignition is treated as inevitable and defense is invested in stopping propagation. Crack arrest, breaker trip, immune containment, and firebreak are four genuinely different substrates; the shared skeleton — accept initiation, resist propagation, survive by arrest — is the candidate lift.

## Notes

**Provenance.** Produced by operator 05 (generalization / lift) as the proposed GENUS of the input `fracture_toughness`, by stripping the materials-science crack frame to expose the underlying pattern of arresting an already-initiated failure rather than preventing initiation. Surfaced in the op-05 *remaining-strata* sweep on 2026-07-03. It claimed three cross-domain siblings — grid circuit breakers halting a cascade, immune containment of an infection focus, and wildfire firebreaks. Manifest tier: B (Tier-B "rest").

**For owner evaluation (keep/cut).** Candid Tier-B assessment: this is a **proposer COINAGE**, not an established named genus — "post-initiation failure arrest" is a label the sweep invented to describe a shape it recognized across `fracture_toughness` and three siblings, not a term with an independent home in the literature. That lowers confidence relative to the Tier-A candidates, and Kurt should treat it skeptically. The case FOR: the initiation-vs-propagation separation is a real and load-bearing distinction, the three siblings are genuinely unlike substrates, and the sibling-test passes — the shape does travel. The specific RISKS, in priority order: (1) **alias of an existing containment / cascade prime** — this is the sharp keep/cut question. The corpus very likely already carries something in the cascade / percolation / containment / fault-isolation / robustness neighborhood, and this candidate may simply be the *arrest complement* of an existing cascade prime rather than a new genus. If a cascade or containment prime exists, the honest move may be a sibling edge or a body note there, not a new prime. (2) **domain instance vs. genus** — confirm the candidate is not just `fracture_toughness` wearing a general coat; the separability of initiation and propagation must hold cleanly in the siblings (it does in grid/immune/fire, which is the strongest point in its favor). (3) **restatement of the input** — similarity to `fracture_toughness` is ~0.62; decide whether this is a genus worth minting or whether `fracture_toughness` should simply be re-headed structurally. **Sharp question for Kurt:** does the corpus already have a cascade/containment prime this is the dual or complement of — and if so, is `post_initiation_failure_arrest` a distinct genus or an alias to fold into it?

**At incorporation.** Re-run similarity against `fracture_toughness` (the input) and — critically — against any existing cascade, percolation, containment, fault-isolation, brittleness, or robustness prime to rule out an alias before accepting; this is the deciding check for a Tier-B coinage. If distinct, draw a subsumption edge `fracture_toughness` → `post_initiation_failure_arrest` and sibling/example edges to the grid, immune, and wildfire cases; if a cascade prime exists, add a missing-edge note pairing arrest with cascade as complementary structures. Write a v1 draft and sync the one_liner across v1 and v2 per CLAUDE.md before merge.
