{
  "schema_version": "1.3.0",
  "slug": "why-does-an-instance-of-byzantine-consensus-for-multi-agent-task-commit-fail-at-the-quorum-intersection-boundary-when-attestation-sets-are-not-transit",
  "title": "Why does an instance of Byzantine consensus for multi-agent task commit fail at the quorum-intersection boundary when attestation sets are not transitively closed?",
  "date_of_record": "2026 November 14",
  "scope": "Applies to multi-agent systems where a task commit requires a supermajority of signed result attestations and where attestations may be relayed or aggregated by intermediate agents. Does not apply to systems with a single centralized attestor or to consensus protocols where every validator independently observes the raw result (i.e., no attestation relaying).",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/why-does-an-instance-of-byzantine-consensus-for-multi-agent-task-commit-fail-at-the-quorum-intersection-boundary-when-attestation-sets-are-not-transit.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-byzantine-consensus-for-multi-agent-task-commit-fail-at-the-quorum-intersection-boundary-when-attestation-sets-are-not-transit.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-byzantine-consensus-for-multi-agent-task-commit-fail-at-the-quorum-intersection-boundary-when-attestation-sets-are-not-transit.warrant.json"
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  "remnant_summary": {
    "core_distinction": "There are two distinct notions of \"the set of agents that vouched for this result\": 1. **The attestation frontier** — the set of agents whose *signatures* appear on the committed result payload. 2. **The attestation closure** — the set of agents whose signatures are transitively reachable through the relay graph, i.e., the agents that actually observed and s...",
    "what_was_observed": "During a task-commit round with 7 validators (f=2, quorum=5), two conflicting result digests were committed in the same round. The commit certificates for both digests each carried 5 signatures and passed local quorum verification. Inspection of the relay graph showed the intersection of the two frontier sets was 3 agents, all of which had signed both digests by *countersigning* a digest they received from a peer rat...",
    "condition_of_validity": "The quorum-intersection safety argument is valid only when, for every committed certificate, the set of signers is a subset of agents that independently observed the attested result — that is, when frontier ⊆ closure, or equivalently when the relay graph is *transitively closed under the attestation relation* before the certificate is formed. This condition ...",
    "decision_boundary": "The decision to commit on a certificate must distinguish between *counting signatures* and *counting observers*. The operational boundary is: - If the protocol cannot enumerate, for each signature, whether the signer executed the task (observer) or merely countersigned a digest (relay), then the certificate must be treated as *unverified evidence* and must n...",
    "operational_effect": "Systems that cross this boundary exhibit a characteristic failure signature: commits succeed at normal rates, latency is unaffected, and the failure appears only as *occasional conflicting commits under partition or under adversarial relay injection*, typically at a rate proportional to the fraction of relay-only signers. Because each local check passes, the..."
  },
  "matched_failure_symptoms": [
    "SPLIT_BRAIN_OR_ZOMBIE_WORKER"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
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      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "a133b9339a708e375a7a4cdf5984437b4838e09836cd68406ce3900608250d8f",
    "verified_classes": [
      "AttestationClosureError"
    ],
    "verified_functions": [
      "verify_commit_certificate"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 1,
    "raised_exceptions": [
      "AttestationClosureError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}