Supplementary amount
12. Until such time as the aggregate of the authorities' supplementary amounts calculated under paragraphs 9, 10 and 11 equals the aggregate of the amounts specified in sub-paragraphs (a), (b) and (c) of the definition of L in paragraph 8, the calculations set out in paragraphs 10 and 11 shall, subject to the modifications set out below, continue to apply to calculate the supplementary amount for those appropriate authorities to which neither paragraph 9 nor 11 has applied; and for that purpose—
(a)O shall apply as if the supplementary amount were the amount calculated under paragraph 10 or, if by virtue of this paragraph there has been more than one calculation, the last amount calculated under that paragraph in respect of that appropriate authority;
(b)P shall apply as if the amount to be deducted to determine the balance of the total amount available were the aggregate of the supplementary amounts for appropriate authorities to which, in the calculation under paragraphs 10 and 11 or, if there has been more than one calculation under those paragraphs, the last such calculation, paragraph 11 applied; and
(c)Q shall apply as if the total of the supplementary amounts were the total of all the supplementary amounts calculated under paragraph 10 or, if by virtue of this paragraph there has been more than one calculation, the last calculated under that paragraph in respect of all appropriate authorities to which paragraph 11 did not apply in that calculation.