ADR 0042: Numeric variation-point ownership

Inventory counts in this record are acceptance-time historical context; the current inventory is owned by the ASL tree and its generated projections.

Historical-evidence note: verification paths named below record the evidence used when this ADR was accepted; deleted aggregate checks are not active architecture or release owners. Current ownership is the four-surface ASL tree, with per-ID AVS coverage projected into spec/evidence/release-traceability-readiness.json.

Decision scope

Numeric result rules and allowed-result sets remain open.

Context

ADR 0095 requires every target-dependent or implementation-defined numeric result to have a discoverable selector and a finite or mathematically testable allowed-result contract. The closed numeric inventory already assigns 108 operations to 20 domains and 30 hooks, but it did not enumerate the individual open dimensions within those domains. In PTO ISA 0.58.0 that inventory contains 104 operations, 18 domains, and 28 hooks. That made it possible to discuss a profile or hook without proving ownership of every unresolved result choice.

The PTO architecture identifies target profiles and numeric variation but does not yet supply complete allowed-result sets. No profile name, equal numeric code, tool behavior, or implementation behavior becomes a numeric owner by implication.

Decision

The generated spec/evidence/numeric-variation-point-ownership.json ledger is the fail-closed discovery and ownership checkpoint for ADR 0095.

1. A variation point is one exact (numeric domain, open dimension) pair from spec/evidence/numeric-contracts.json. The current inventory contains 99 points across all 20 domains.
2. Every point remains owned by the portable pto-numeric-v1 architecture contract until an accepted PTO decision explicitly delegates that exact point to a named target profile or visible numeric selector, or marks the applicable operation/type/profile tuple unsupported.
3. The ledger maps every point to its complete operation and hook reachability. Separate operation and hook tables prove that all 108 operations and all 30 hooks, including two library-only helpers, have one explicit owner boundary.
4. A target profile identity, selector namespace, backend behavior, or equal numeric code does not create a result rule. Delegation requires an accepted record, exact applicability, selector identity, and bounded allowed-result contract.
5. Unknown profiles, modes, formats, tuples, or missing delegated rules reject before architectural effects. The existing A2/A3 MX applicability decision remains the only accepted unsupported numeric slice: 150 tuples and zero result rules.

Consequences

S5-T2-A4 closes variation-point discovery and current-owner assignment. It does not accept a numeric result, delegate a variation point, populate an allowed-result set, or close ADR 0095. The generated ledger therefore records 99 portable-owner rows, zero accepted delegations, zero bounded result contracts, and zero accepted domain result rules.

ADR 0095 closes only after every non-portable row names its accepted profile or visible selector, bounds its results, and has unknown-selection and missing-rule rejection evidence. The other 11 numeric decisions, all 20 domain rules, oracle qualification, vectors, differential execution, adjudication, and independent approval remain open. The maturity floor remains M4.

The current ASL model has no generic named-target-profile selection boundary. This checkpoint therefore proves evidence ownership only; it does not claim executable rejection of an unknown profile. When that selection surface is introduced, its unknown-profile and missing-rule paths require explicit pre-effect tests before ADR 0095 can close.

Evidence

• spec/evidence/numeric-variation-point-ownership.json
• scripts/generate-numeric-variation-point-ownership
• spec/evidence/numeric-contracts.json
• spec/evidence/numeric-profile-decision-inputs.json
• spec/catalog/numeric-profile-identities.json
• spec/evidence/numeric-rounding-selector-contract.json
• spec/evidence/numeric-format-namespace-contract.json
• spec/evidence/numeric-profile-applicability-closure.json
• spec/profile-hooks.json
• scripts/check-catalogs