Items subject to adjustment may consist of deductions taken or not taken in prior years, or amounts of income required to be included or excluded in such years, but such items shall be disregarded to the extent it can be shown that the prior treatment of such items had no actual effect on the amount of Oklahoma income tax paid; in making such showing, no items other than the items subject to this transitional adjustment shall be considered.
No net addition to Oklahoma taxable income shall be required by reason of this section, but, at the election of the taxpayer, a deduction in the amount of such net adjustment shall be available as provided below.
Okla. Stat. tit. 68, § 2354