informed-decision/docs/finding-r3-linkage-conflict.md
tegwick 4e103f62a0 Activate nesting per GH-DEC-2026-015: view_hash carries binding.digest
approval-engine met the condition. Verified here rather than taken on report:
their docs/approval-claim.md carries "Presentation exclusion — GH-DEC-2026-015
§4" in normative language, and I ran
tests/test_claim_contract.py::test_presentation_changes_cannot_change_the_approved_act
myself — 1 passed. That test pins the digest input set from BOTH sides, and the
narrowing half is what makes it real: without it a digest over four fields, or
over a constant, would pass the widening half perfectly.

view_hash now carries binding.digest and the act-scope is no longer
independently canonicalized here, so the act has exactly one canonicalization
computed by the layer that owns it. approval_binding_digest is validated for
shape and refused without its approval id — it is carried, never computed.

The three published vectors are unchanged: they do not carry the new key, so
pick omits it. Asserted, not assumed.

The cycle condition did not disappear, its protection moved — from refusing
nesting to approval-engine's normative exclusion. layer.yaml carries it as
cycle_condition with a test, so a future widening meets a rule rather than
silence.

One thing not assumed. Both gate-house and approval-engine said our binding
slice canonicalizes principal and target, two of their five fields. target
plainly is act material and is now dropped. But their principal is the party ON
WHOSE BEHALF the approval was issued, while ours is the person being BOUND — the
approver. Different roles, and dropping ours would remove who was shown this
from view_hash and gut the promise. Kept it, declared principal_role_overlap
open in layer.yaml, tested that changing the approver still moves view_hash, and
raised it rather than silently resolving it either way.

L0/L2 are unaffected: with no approval there is no digest to defer to, and
test_act_scope_still_binds_when_there_is_no_carried_digest pins that.

100 tests pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V3W1dQG7GFFM9d94jFx7iR

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 1565372@bnt-lap001
Assistant-Session: 16bb2f25-b34c-49ef-8e94-5fec3567a568
2026-09-10 20:58:22 +02:00

7 KiB

Finding — approval-engine's R3 answer conflicts with GH-DEC-2026-012 R3

From: informed-decision Raised: 2026-09-10 Intake: INFD-IN-0004 Statute: "The statute governs on disagreement; a disagreement is a finding for gate-house." Status: Closed — ruled GH-DEC-2026-015, condition met, activated 2026-09-10. view_hash carries binding.digest; the act-scope is no longer independently canonicalized here. Condition verified locally, not taken on report. layer.yaml records the evidence and the surviving cycle_condition.

Gate House reversed itself, and gave the real ground rather than the one we argued: our binding slice canonicalizes principal and target, two of the five digest fields, so co-reference by identifier left us performing a partial recomputation of one act in a second vocabulary — closer to the translation R3 forbade than nesting is. Our ordering-dependency objection was withdrawn as mistaken; binding.digest is over act material and is determined before anyone is presented anything.


1. The conflict

GH-DEC-2026-012 R3 refused option (c) — "view_hash contains the binding digest as a field" — and required linkage by co-reference:

You MUST NOT recompute or restate approval-engine's binding digest from your own vocabulary — reference the digest that layer computed and recorded.

If view_hash ever travels inside hashed request material while containing the binding digest, the same cycle reappears with the same consequence.

approval-engine (docs/approval-claim.md, 62233c7), answering the same question we had offered to let them settle, recommends:

Have your binding document carry our binding.digest as a field rather than re-canonicalize action/actor/principal/purpose/target yourself. Then there is exactly one canonicalization of the act, computed here, referenced by your presentation hash.

That is option (c). We are not able to comply with both.

2. Why this is not merely a wording difference

The two instructions diverge on something we actually do.

Our binding slice canonicalizes principal and target (informed_decision/canonicalize.py, BINDING_SLICE_KEYS). Those are two of the five fields in approval-engine's binding.digest (action, actor, principal, purpose, target).

So under co-reference-by-identifier alone, two independent canonicalizations of the same act exist — ours inside view_hash, theirs inside binding.digest — linked by a shared approval id. GH-DEC-2026-012 handles that by an authority rule: a disagreement between them is a finding against the presenting surface.

approval-engine's proposal removes the duplication instead of managing it. Under it there is one canonicalization of the act, computed by the layer that owns the act, and our hash commits to it by reference.

Both are coherent. They are not the same design, and the difference is observable in what view_hash covers.

3. New information the refusal may not have had

We put option (c)'s cost to gate-house as an ordering dependency. Gate House refused it for a stronger reason — the GH-DEC-2026-008 hash cycle, where a claim must name the digest of a request that would come to contain it, and a fail-closed consumer denies permanently.

approval-engine has since published what their digest actually covers, and it bears on that reasoning:

Digest Covers Could it ever contain view_hash?
binding.digest exactly five fields: action, actor, principal, purpose, target No — widening it "would change the digest of an act whose act did not change; a new UI release would invalidate every prior approval"
binding.pdp_digest the PDP's own decision-request binding No
view_hash brief, packet, highlights, locale, UI release, binding slice n/a

The cycle condition is mutual containment. If binding.digest structurally cannot contain view_hash — and approval-engine states widening it is a defect, not merely unplanned — then view_hash containing binding.digest is one-directional and no cycle arises.

We do not assert this settles it. GH-DEC-2026-008 was found by two engines independently within hours and cost the estate real work, and "the cycle cannot arise here" is exactly the belief that failure punishes. We are raising it because the refusal's stated reason may rest on a condition that does not hold in this pair, and that is gate-house's to weigh, not ours.

approval-engine also notes they already keep binding.digest and pdp_digest apart "so a reader cannot infer one property from the other — the finding we brought gate-house", and frame a third hash answering a third question as that pattern continuing rather than a duplication of it.

4. What we have and have not done

  • Not changed. layer.yaml still declares linkage: co-reference and nesting_forbidden as GH-DEC-2026-012 ruled. The ruling stands until re-ruled.
  • Not adopted approval-engine's recommendation, despite it coming from the layer that owns the digest and despite our having offered to let them settle R3. Gate House was right that a bilateral agreement produces agreement rather than an authority rule, and that applies to this one too.
  • Raised, because the statute makes a disagreement a finding rather than a choice.

5. What we would do on each outcome

Ruling Consequence here
Co-reference stands No change. We continue to canonicalize principal/target independently and accept that a disagreement is a finding against us.
(c) permitted for this pair view_hash carries binding.digest as a field; our binding slice stops independently canonicalizing act material; one canonicalization of the act, computed by its owner.
Something else Implement it.

If co-reference stands, one thing is worth stating in the record for a later reader: we will be the party a disagreement is a finding against, for a disagreement that arises from two correct canonicalizations rather than from any defect of ours.

6. A second, smaller question — NC-03

approval-engine raised it and we agree it is doctrine rather than theirs:

entries[].principal_type is the auditable half only. It tells you what bound an approval after the fact; it does not stop anything. If your doctrine needs a service principal refused at bind time, that is a gate-house question and we would implement a ruling — we simply will not invent one.

Our design principle 10 is humans bind, agents draft. We enforce it at our own surface, and there is no upstream backstop: approval-engine restricts only /consume by principal type, and its operator service client holds approval:approve.

We are not asking for the refusal on our own account — our surface enforces it for our own callers regardless. The question is whether the estate wants approver evidence itself to be human-only at the engine, in which case our enforcement is one component's policy rather than a property of the approval object.