Stage D: the conditional relational alternative

This is X-Enter's conditional circuit XEnter. It detects $\cos \theta$, not a globally faithful encoding of the real $I_{\mathrm{rel}}$.

The raw even-parity probabilities are

which need not be invariant. The proved boundary is the coarse output $F,+,-$. If a further accessible log retains the raw distinction, that larger boundary must be tested separately. No failure is discarded or renormalized away.

The finite circuit is constructed at its abstract input. Its physical application still lacks the independently charged classical reference and its preparation/acquisition interface.