((a)) In this section, the current redemption value of an obligation issued on a discount basis and redeemable before maturity at the option of its holder is deemed to be the face amount of the obligation.
((b)) The face amount of obligations issued under this chapter and the face amount of obligations whose principal and interest are guaranteed by the United States Government (except guaranteed obligations held by the Secretary of the Treasury) may not be more than $14,294,000,000,000, outstanding at one time, subject to changes periodically made in that amount as provided by law through the congressional budget process described in Rule XLIX of the Rules of the House of Representatives or as provided by section 3101A or otherwise.
((c)) For purposes of this section, the face amount, for any month, of any obligation issued on a discount basis that is not redeemable before maturity at the option of the holder of the obligation is an amount equal to the sum of—
((1)) the original issue price of the obligation, plus
((2)) the portion of the discount on the obligation attributable to periods before the beginning of such month (as determined under the principles of section 1272(a) of the Internal Revenue Code of 1986 without regard to any exceptions contained in paragraph (2) of such section).