s 405 The aggregate tax-EBITDA of a worldwide group
For the purposes of this Part “the aggregate tax-EBITDA” of a worldwide group for a period of account of the group is— (a) the total of the tax-EBITDAs for the period of each company that was a member of the group at any time during the period, or (b) where the amount specified in paragraph (a) is negative, nil.