In the absence of an express exemption from State income taxes, no treaty of the Federal Government shall be construed to exempt a corporation from the taxes imposed under Articles IV and VI. For purposes of determining "taxable income" under Article IV, any corporation not subject to Federal income taxation or Federal reporting requirements pursuant to such a treaty shall be required to file a report with the department showing the taxable income which would have been reported to and ascertained by the Federal Government had it not been exempted by the treaty.
72 P.S. § 10003.11