(4)[ Notwithstanding anything to the contrary contained in section 10-A or section 10-AA or section 10-B or section 10-BA or in any provisions of this Chapter under the heading "C.-Deductions in respect of certain incomes", where, in the case of an assessee, any amount of profits and gains of an undertaking or unit or enterprise or eligible business is claimed and allowed as a deduction under any of those provisions for any assessment year, deduction in respect of, and to the extent of, such profits and gains shall not be allowed under any other provisions of this Act for such assessment year and shall in no case exceed the profits and gains of such undertaking or unit or enterprise or eligible business, as the case may be.
