I have a partnership that owns one rental property. Is not subject to section 163 limitations for interest expense. The basis worksheet is reducing basis for the K-1 loss which has mortgage interest expense included in the loss on the K-1, plus adding the partners share of interest expense to the total loss  on line 10 of the basis worksheet. The result is basis is decreased for the interest twice.

The basis worksheet has the interest expense on line 4 b. It says if 4a less 4b is less than zero to include the interest expense on line 10.

What am I missing?