Interface contract: Geometry-only interface

A configuration contains:

1. a labelled polygonal slice or a labelled one-sided slice germ;

2. a geometric particle packet specifying an identifier, deficit, worldline, reference rest vector, and particle-cell label;

3. an exact clock and a finite permission register;

4. for a fixed finite list of original matter names, one declared cell location per name;

5. an internal matter state.

A geometric rule, called a $G$-rule, may inspect the declared geometric data and geometric control registers. Its guard, geometric output, certificates, and cell-label transport must not depend on the number of matter names or on their internal state. Applying a fixed cell-label transport to each original name is permitted.

At the event considered here:

1. no measurement or coupling rule is applied;

2. the internal matter factor is acted on by the identity;

3. the particle identifier is geometric data, not a test of matter occupancy;

4. rounded reports are auxiliary and do not determine the event guard;

5. implementation history is not a geometric observation;

6. decoder correctness is required on a declared forward event domain, not on intermediate compiler states.