A single-molecule work claim cites checked trap and extension sources. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
The audit starts from calibrated trap force
The hidden trap source cites stiffness 2, displacement 3 metres, and force 6 newtons.
2⋅3=6
The same force and extension close the work ledger
The checked work distance is 6 metres, so work is 36 joules.