This section applies where, on a disposal of trust business assets, there is (in addition to the qualifying beneficiary) at least one other beneficiary who, at the material time, has an interest in possession in—
Only the relevant proportion of the amount which would otherwise result under subsection (1) of section 169N is to be treated as so resulting.
And the balance of that amount, ... , is accordingly a chargeable gain for the purposes of this Act.
For the purposes of this section "the relevant proportion" of an amount is the same proportion of the amount as that which, at the material time—
In subsection (4) "the qualifying beneficiary's interest" means the interest by virtue of which he is the qualifying beneficiary (and not any other interest the qualifying beneficiary may have).
In this section "the material time" means the end of the latest period of 2 years which ends not earlier than 3 years before the date of the disposal and—