The term “bond” includes any obligation.
The term “governmental unit” does not include the United States or any agency or instrumentality thereof.
Property shall be treated as owned by a governmental unit if it is owned on behalf of such unit.
In the case of any residence with respect to which financing is provided from the proceeds of a tax-exempt qualified mortgage bond or qualified veterans’ mortgage bond, if there is a continuous period of at least 1 year during which such residence is not the principal residence of at least 1 of the mortgagors who received such financing, then no deduction shall be allowed under this chapter for interest on such financing which accrues on or after the date such period began and before the date such residence is again the principal residence of at least 1 of the mortgagors who received such financing.
In the case of any facility with respect to which financing is provided from the proceeds of any private activity bond to which this paragraph applies, if such facility is not used for a purpose for which a tax-exempt bond could be issued on the date of such issue, no deduction shall be allowed under this chapter for interest on such financing which accrues during the period beginning on the date such facility is not so used and ending on the date such facility is so used.
Any use with respect to facilities financed with proceeds of an issue which are not required to be used for the exempt purpose of such issue shall not be taken into account.
In the case of any facility where part but not all of the facility is not used for an exempt purpose, only the interest accruing on the financing allocable to such part shall be taken into account.
Any qualified scholarship funding bond, and qualified student loan bond, outstanding on the date of the issuer’s election under this paragraph (and any bond (or series of bonds) issued to refund such a bond) shall not fail to be a tax-exempt bond solely because the issuer ceases to be described in subparagraphs (A) and (B) of paragraph (2) if the issuer meets the requirements of subparagraphs (B) and (C) of this paragraph.