In the case of a part realisation, any reference in section 755 or 758 to the appropriate proportion of the cost of the old asset is to the following proportion of it—

$\frac{\mathrm{AVB}-\mathrm{AVA}}{\mathrm{AVB}}$

where—

AVB is the accounting value immediately before the part realisation, and

AVA is the accounting value immediately after the part realisation.

If the old asset has previously been the subject of a part realisation, the reference in subsection (1) to the cost of the old asset is a reference to the adjusted cost.

References in sections 755 and 758 and subsection (2) to the adjusted cost are references to the cost of the old asset, less the sum of the amounts given by subsections (1) and (2) in relation to earlier part realisations.