Module grammar 

DSFB-Debug: grammar evaluation — paper §5.5.

Maps the per-(window, signal) SignTuple σ(k) = (‖r‖, ṙ, r̈) to one of three GrammarState symbols:

• Admissible — within envelope; drift inward or bounded
• Boundary — approaching envelope with sustained outward drift (early-warning state)
• Violation — exited envelope (structural fault / actionable incident)

The decision is a pure function of σ(k) and the operator-supplied grammar thresholds (drift_threshold, slew_threshold, envelope_radius). The downstream policy.rs applies hysteresis (n_confirm windows) before producing the operator-facing confirmed_grammar_state.

The grammar is the load-bearing structural-detectability mechanism (paper Law 1): a trajectory that drifts persistently outward is more detectable — and more interpretively significant — than one that oscillates at larger amplitude within admissible bounds.

Functions

evaluate_raw_grammar

Evaluate raw grammar state from sign tuple and envelope parameters.

hysteresis_confirm

Apply hysteresis confirmation: raw state must persist for n_confirm consecutive windows before being committed.