Leaked shots remain visible as a separate budget line. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Leaked shots are carried outside readout

The leakage stage carries 20 leaked shots outside the zero and one readout ledger.

Nleaked=20N_{\text{leaked}}=20
Leaked shots carriedThe audit keeps leaked shots visible.1zero0one4/5zero1/5one4/5kept1/5lost4/5kept1/5lost3/5coherent2/5dephasedtrue probabilitieszero 4/5one 1/5assignmentobserved probszero 13/20one 7/20over 80 shots52 zero reads28 one readsprep -> error -> phase -> readchannel inputafter errorzero leakageone leakagephase loss

Observed plus leaked closes the prepared budget

Observed reads are 52 zero and 28 one. With 20 leaked shots, the total returns to 100.

52+28+20=10052+28+20=100
Open-system closureNo leaked count disappears into readout.1zero0one4/5zero1/5one4/5kept1/5lost4/5kept1/5lost3/5coherent2/5dephasedtrue probabilitieszero 4/5one 1/5assignmentobserved probszero 13/20one 7/20over 80 shots52 zero reads28 one readsprep -> error -> phase -> readchannel inputafter errorzero leakageone leakagephase loss