For purposes of this section, the term “regular tax” means the regular tax liability for the taxable year (as defined in section
26
(b)) reduced by the foreign tax credit allowable under section
27
(a), the section
936 credit allowable under section
27
(b), and the Puerto Rico economic activity credit under section
30A. Such term shall not include any increase in tax under section
45
(e)(11)(C),
49
(b) or
50
(a) or subsection (j) or (k) of section
42.