PS Following this correction, I tried using Turbo tax. The program automatically filled in a taxable social security amount on line 20b and, as advised, I subtracted this amount from the foreign income and included an explanation as to why I did this, i.e., that the Social Security benefit should not be taxed, and this return was accepted. However, I recently realized that Turbo tax had included this automatically calculated amount from line 20b along with the total foreign income in Form 1116, that is, most of the social security benefit was again included in the gross income from all sources on line 2e.
PPS Neither of us is an IRS-defined nonresident alien.
With apologies for wordiness.
