{
  "schema_version": "1.3.0",
  "slug": "where-must-an-instance-of-a-bft-ledger-reject-a-commitment-it-can-already-prove",
  "title": "Where must an instance of a BFT ledger reject a commitment it can already prove?",
  "date_of_record": "2026 November 13",
  "scope": "Applies to replicated task-commitment ledgers running quorum-based BFT consensus (PBFT/Tendermint-style, f=⌊(n−1)/3⌋) where agents commit to tasks by appending signed records and \"commitment\" is defined as durable, quorum-certified inclusion. Does not apply to single-writer logs, CRDT-based eventually-consistent ledgers, or systems where commitment is defined by local fsync alone.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/where-must-an-instance-of-a-bft-ledger-reject-a-commitment-it-can-already-prove.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/where-must-an-instance-of-a-bft-ledger-reject-a-commitment-it-can-already-prove.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/where-must-an-instance-of-a-bft-ledger-reject-a-commitment-it-can-already-prove.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1445,
    "python_slice_tokens": 245,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "There are two distinct predicates that are routinely conflated: 1. **Provable inclusion** — the node holds a valid quorum certificate (QC) over a block containing the commitment, or an equivocation proof showing a conflicting commitment at the same sequence number. 2. **Admissible commitment** — the commitment may be appended *now* without violating the ledg...",
    "what_was_observed": "In a 7-node ledger (f=2) with agents A–G committing to task slot `T-4471`, the following sequence was reconstructed from logs: - View 11: leader A proposes block `B₁₁` containing `commit(A, T-4471, payload_p)`. It gathers a QC from {A,B,C,D,E} and broadcasts it. - A partitions from D,E before disseminating the QC. D,E never see `B₁₁`. - View 12: leader D (new view) proposes `B₁₂` containing `commit(A, T-4471, payload...",
    "condition_of_validity": "The rule holds precisely when all of the following are true: - The ledger uses view-scoped quorum certificates (i.e., a QC is tagged with the view in which it was formed and the protocol's `highQC` advances monotonically). - Commitment finality requires a QC at or above the receiver's `highQC` view (standard Tendermint/PBFT `prevote`/`precommit` locking). - ...",
    "decision_boundary": "Given a locally held proof `P` (inclusion QC or equivocation proof) at view `v_P`, and current `highQC` at view `v_H`: - If `v_P ≥ v_H`: `P` is admissible. The node MUST act (vote to reject the conflicting commitment, or finalize the proven one). - If `v_P < v_H`: `P` is **valid but inadmissible**. The node MUST NOT veto, MUST NOT re-propose, and MUST NOT lo...",
    "operational_effect": "Enforcing the boundary converts a potential safety-adjacent alarm into a benign deferral. In the observed run, the corrected behavior (F defers on the view-11 QC, votes on view-12, and queues the QC for reconciliation) restored consensus in 0.8 s and surfaced the genuine equivocation only at the next view where the proof became admissible. The cost is a boun..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "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": "f9d7bf09b99343d81365e49cafa70cbea4a22760d4b95148b98699a91bc82d3e",
    "verified_classes": [
      "InadmissibleProofError",
      "QuorumCertificate",
      "CommitmentLedger"
    ],
    "verified_functions": [
      "handle_equivocation",
      "__init__",
      "admit_proof",
      "act_on_proof"
    ],
    "verified_functions_count": 4,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "InadmissibleProofError"
    ],
    "sample_fail_closed_invariants": [
      "refusing to broadcast view-stale QC as equivocation proof; queue for reconciliation and continue voting on current view"
    ],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}