The audit begins by carrying the retained survival count into later budgets. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Prepared shots reduce before readout
The audit starts with 80 prepared shots and retains 60.
Nretained=60
The retained count becomes the next budget
The phase budget must start with the same 60 retained shots. The capstone check rejects a mismatch.