# Engine Schemas (SFT)

These JSON schemas are the SFT analogue of the certificate and obstruction contracts used in your RU flagship work.

They are intentionally small and stable:

- `witness_stability_certificate_schema.json` (WSC): stores witness tier, mechanism, value, perturbation model, margins, assumptions, and artifact links.
- `witness_obstruction_schema.json` (WOB): stores a named failure mode with evidence and next moves.
- `universality_report_schema.json`: stores the scoped universality thesis, claim ladder, nonclaims, theorem index, and artifact index.

Design goal

- Every strong universality sentence should be traceable to either a WSC or a WOB, plus a theorem reference.

## WOB obstruction codes

The WOB schema enumerates core obstruction modes used by the witness engines.

- WOB-0-slope-zero: phase response is trivial
- WOB-1-no-subsystem: no meaningful embedded subsystem is available
- WOB-2-trivial-winding: all tested loops have degree zero
- WOB-2-orbit-collapse: no circle-type orbit exists in the claimed forcing domain on which an equivariant response can act (for example the symmetry is not realized on the domain)
- WOB-3-pinch: image misses an arc on the intended subsystem
- WOB-3-equivariance-defect: the observable is not genuinely equivariant in the adopted model class
- WOB-4-tear: regularity fails so invariants are not definable
- WOB-5-holonomy-defect: lift/connection consistency fails for the intended holonomy mechanism
- WOB-6-coupling-mismatch: wrong target torus used when coupling constraints define a CST
- WOB-7-mixing-not-justified: mixing claim made without a justified diffusion/noise model
- WOB-8-resonant-locking: rank deficiency collapses the intended torus target
- WOB-9-disconnected-slice: domain disconnect prevents realizing coverage on the intended slice component
