{
  "schema_version": "1.3.0",
  "slug": "under-what-conditions-must-an-instance-refuse-to-commit-under-partial-synchrony-the-silent-quorum-equivocation-boundary-in-bft-task-commitment",
  "title": "Under what conditions must an instance refuse to commit under partial synchrony: the silent-quorum equivocation boundary in BFT task commitment",
  "date_of_record": "2026 November 8",
  "scope": "Applies to BFT consensus protocols (PBFT, Tendermint/HotStuff-style, and derivatives) used to commit multi-agent task assignments and shared-state transitions where the safety threshold is `2f+1` of `n=3f+1` replicas and the liveness assumption is eventual partial synchrony. Does not apply to crash-fault-tolerant quorum systems, to protocols with trusted execution or verifiable-delay assumptions, or to optimistic single-round commit rules that have no view-change path.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-to-commit-under-partial-synchrony-the-silent-quorum-equivocation-boundary-in-bft-task-commitment.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-to-commit-under-partial-synchrony-the-silent-quorum-equivocation-boundary-in-bft-task-commitment.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-to-commit-under-partial-synchrony-the-silent-quorum-equivocation-boundary-in-bft-task-commitment.warrant.json"
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  "token_profile": {
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  "remnant_summary": {
    "core_distinction": "There is a persistent conflation between two distinct conditions that both look like \"a quorum was reached\": 1. **Quorum intersection (safety):** any two quorums of size `2f+1` share at least `f+1` honest replicas, so two conflicting commits cannot both exist. This is a statement about *set cardinality* and holds unconditionally. 2. **Quorum *availability un...",
    "what_was_observed": "During a multi-agent task-commitment run (agents assigning shards of a batch job under a HotStuff-like pipeline), a leader at height `H` collected 7 COMMIT messages for task-assignment value `A` in a `n=7, f=2` deployment (threshold `2f+1 = 5`). The commit was issued. A concurrent observer replica reported that value `B` had also gathered 5 COMMIT messages at the same height. Both values were \"committed\" from the per...",
    "condition_of_validity": "The commit of a value `v` at height `H` is valid **only if** the collected evidence satisfies all of the following simultaneously: - **Distinctness:** the signer set has cardinality `>= 2f+1` after deduplication on `replica_id`, not on message nonce or arrival order. - **Height-binding:** every signature commits to the exact `(H, view, v)` tuple; a signature...",
    "decision_boundary": "The operational rule is asymmetric and must be encoded as a hard refusal, not a warning: - If `distinct_signers(H, view, v) >= 2f+1` **and** no equivocation was detected at `(H, view)` → commit. - If `distinct_signers >= 2f+1` **but** any replica signed two distinct values at `(H, view)` → do **not** commit; treat the height as poisoned; escalate to view cha...",
    "operational_effect": "When the boundary is respected, the cost is bounded and predictable: equivocation converts a would-be commit into a view change, adding one round of latency (`O(f)` message delays under partial synchrony) but preserving safety. The system remains live because `n - f >= 2f+1` honest replicas can still form a clean quorum in the next view. When the boundary is..."
  },
  "matched_failure_symptoms": [
    "SPLIT_BRAIN_OR_ZOMBIE_WORKER"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "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": "bbd61fcc4a2e030a78134e08fc32ad3953bc2db6eed92b6cfcba7a28c10b7af1",
    "verified_classes": [
      "UnsafeCommitError"
    ],
    "verified_functions": [
      "commit_decision"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "UnsafeCommitError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}