(1) In this section -
"petroleum profits on which corporation tax falls finally to be borne", in relation to a company, means the amount of the petroleum profits of the company after making all deductions and giving or allowing all reliefs that for the purposes of corporation tax are made from, or given or allowed against, or are treated as reducing-
(a) those profits, or
(b) income or chargeable gains, if any, included in those profits;
"relevant petroleum lease" means a petroleum lease in respect of a relevant field, being a field discovered by petroleum exploration activities carried on under a licence (other than a petroleum lease) which authorises the carrying on of those activities for a period which, apart from any extension of the period or revision or renewal of the licence-
(a) is not longer than 10 years, where the petroleum lease is granted by the Minister for the Marine and Natural Resources before the 1st day of June, 2003,
(b) is longer than 10 years but not longer