Module axis_role 

Normative axis-role taxonomy for the .10d container header.

Each of the ten tensor axes [q, v, w, x, y, z, t, alpha, mu, sigma] is declared in the header with one of the roles below. The taxonomy is the prerequisite for honest queryability: a COORDINATE participates in distance, a SELECTOR is excluded from every distance sum, and a CARRIER is the in-band provenance lane. mu carries a dual role (it is both a measured coordinate and the provenance carrier) and so gets its own variant CoordinateCarrier.

Status: PROPOSED, not yet frozen. Timothy Charles Holborn confirmed the Option A assignment on 2026-07-04 as the baseline to encode, but the taxonomy is not normatively frozen in the .10d v1 spec until the P0.7 conformance vectors land. The parser in crate::container_10d::header accepts any non-Undefined assignment today; a future task can tighten it to reject deviations from the frozen table once blessed.

Reference: docs/plans/native-computational-geometry.md §4.1, and the execution plan’s ⚑ “Axis-role taxonomy sign-off” curation datum.

Enums

AxisRole

The role a single tensor axis plays in the .10d distance/query model.

Constants

AXIS_ORDER

Canonical axis order — matches the Tensor10D field order exactly so a Tensor10D can be reinterpreted as ten f32 lanes in this order without re-shuffling. Index i here is index i into axis_roles in the header and into the folded_axes bitmask of super::metric_check.

COORDINATE_AXES

Axis indices for the seven COORDINATE lanes (the ones that may participate in distance). μ is included here because it is a coordinate in addition to being the carrier.

MU_AXIS

Index of μ — the dual-role coordinate + provenance carrier.

PROPOSED_AXIS_ROLES

The proposed (not-yet-frozen) normative axis-role table, indexed by AXIS_ORDER. This is the Option A assignment Timothy confirmed on 2026-07-04:

SELECTOR_AXES

Axis indices for the three SELECTOR lanes (excluded from every distance sum).