Direct IELR decision dossier
I001 is NO-GO for release promotion. An experimental direct IELR implementation may exist behind an explicit opt-in, but it is not authorized as the default or as a release-readiness claim; I002 remains blocked. This decision is a feature gate, not a claim that direct IELR has no future value.
The machine record marks the decision final_no_go, its basis repository_evidence, and its review state validated. The reviewed evidence date is 2026-08-19 at revision 5c569ceaf06e9fb217ea5211194d605bbbc3e2ff. It asserts no signer, consent, or personal decision attribution.
The closed machine record is direct-ielr-decision-v1.json, validated by direct-ielr-decision-v1.schema.json. Run its evidence and policy gate with:
bundle exec ruby -Ilib -r./tool/quality/direct_ielr_decision \
-e 'Ibex::Quality::DirectIELRDecision.new.verify!'Decision rules
A GO requires every GO condition. A single NO-GO condition is sufficient. The machine dossier is the canonical source for the conditions, statuses, and observed evidence rendered below.
| GO condition | Status | Current evidence |
|---|---|---|
| Representative practical canonical cost | Not satisfied | one measured real grammar; at least two representative real grammars are required |
| Ielr required by representative grammars | Not satisfied | zero real IELR-required workloads and zero semantically reviewed conflict removals |
| Algorithm and specification owner | Not satisfied | no accepted owner is recorded |
| Noncanonical verification plan | Not satisfied | no accepted scale-independent verification plan; current verification requires full canonical LR(1) |
| Maintenance budget accepted | Not satisfied | no accepted maintenance budget is recorded |
| NO-GO condition | Status | Current evidence |
|---|---|---|
| No real ielr required workload | Satisfied | zero real workloads currently require IELR |
| Canonical lr1 completes within current measured budget | Satisfied | the one measured real grammar completes canonical LR(1) without observed exhaustion; no broader budget claim is made |
| Lr1 or grammar rewrite is simpler | Not assessable | there is no concrete real conflict case on which to compare alternatives |
| Verifier still enumerates full canonical collection | Satisfied | default and strict ielr1 verification both enumerate full canonical LR(1) |
| Only state count benefit | Satisfied | no semantic conflict-removal benefit is established; structural state and item counts alone do not justify direct IELR |
Bound observations and verification gaps
Measured real grammars: 1. Verified public checkouts: 0. Real IELR-required workloads: 0. Semantically reviewed conflict removals: 0.
Current real workload ibex-frontend records:
| Measurement | Value |
|---|---|
| LR(0) states | 227 |
| LR(0) items | 633 |
| Canonical states | 456 |
| Canonical items | 10482 |
| Final states | 227 |
| Unresolved IELR conflicts | 0 |
Canonical scale status: unresolved. Current verified workflow: default_and_strict_ielr1_verification_enumerate_full_canonical_lr1. Scope: completion is established only for the one measured real grammar; no general scale bound is claimed
V001 verification gaps remain explicit:
ielr_adequacy:not_verifiedsplit_witnesses:not_verifiedconflict_preservation:not_verified
Reconsideration gate
Reconsideration requires all of the following new evidence:
- Representative real grammars: at least two verified representative real grammars.
- Material canonical cost: material canonical state or item cost, or observed bounded exhaustion, on those grammars.
- Meaningful ielr need: IELR removes semantically reviewed meaningful conflicts on those grammars.
- Scale independent verification: a bounded verification plan does not make full canonical LR(1) enumeration mandatory.
- Algorithm and specification owner: an identified owner accepts the algorithm and specification.
- Maintenance budget: the ongoing implementation, verification, review, and maintenance budget is accepted.
State-count reduction without a real semantic or operational need does not reopen the gate.
Legal and implementation provenance
Design lineage: independent_design_from_papers_and_specifications. Permitted design inputs: papers, specifications. GPL implementation source used: false. GPL implementation source translated: false.
future direct IELR design must remain independent; GPL implementation source must not be inspected or translated
Evidence identity
The machine dossier binds the evidence sources by path and SHA-256. It also binds:
- H005 capture base revision
2a5e48aa8008e33f7bb30ccdbd0417141a71e68b; - H005 bound-path digest
422bae34d6893296c4a4c8c0317cedf5b155a3f220368ce6b4550838553fd83c; - H005 implementation digest
91160673bb0d540a738a698781b283d332729c5afafee6a601b14928b1ed3239; - V001 revision
f9d2c54eb4b27fc5ffe798bb0b29d038d97ee35c.
| Source ID | Path | Role | SHA-256 |
|---|---|---|---|
h005-human-report | docs/records/profiles/construction-profiling.md | H005 thresholds, observations, NO-GO rationale, and reconsideration evidence | e69e88b9a474fb07b30d1e29a353e0d80edcced7d538b9ca3cf47413d087034c |
h005-machine-evidence | tool/profile/evidence/construction-profile-v1.json | machine-readable workload measurements, thresholds, decision, and capture provenance | 5ea9321d3ae2278882367fe212677647eeb316ef786cecdedfa67fcda126e223 |
h005-evidence-schema | schema/construction-profile-v1.schema.json | closed H005 evidence contract | 0cdac1514e965800701286084c18411a190ac424527ebf9de2163cbc204b4462 |
v001-trust-boundary | docs/policy/verifier-trust-boundary.md | verifier reference cost, assurance boundary, and explicit IELR non-goals | 7615c078e856bad5b3b8b6606b39dc1b35fedc385da5ab7bbecd1c71b1376b93 |
v001-reference-collection | lib/ibex/verify/reference_collection.rb | independent reference collection implementation reviewed by V001 | d07e900652c61ddd942380d49edce0a3c811605cd82490c1e0e6db54010746fb |
v001-verifier | lib/ibex/verify/verifier.rb | current verifier checks reviewed by V001 | 934ae84111581d2edd4230b06733f259bbf72839042a67c62d20558973af2e2e |
Aggregate source-list digest: a01b664cdd9b77a417105872dfc78efafbc4256d374a97814813419dd3de7549.
Exact reviewed history is part of the evidence contract. A shallow checkout that omits the decision or V001 revision fails closed with an unavailable revision error. Jobs running this gate must fetch complete history; they must not silently weaken source verification to accommodate a depth-one checkout.