(1) "Adjusted base year tax liability" means the taxpayer's corporation net income tax liability under this article, for the tax year ending immediately on or before December 31, 2008, before application of any surtax, alternative minimum tax or credit allowed, authorized or imposed under this chapter, adjusted by:
- (A) Adding the base year liabilities, if any, of affiliates, subsidiaries and related entities that are included in the taxpayer's current year combined report, but which were not included in the taxpayer's base year filing configuration, and
- (B) Subtracting the base year liabilities, if any, of affiliates, subsidiaries and related entities that were included in the taxpayer's base year filing configuration, but that are not included in the taxpayer's current year combined report.