Section 401(c)(2)(A) provides that:

“earned income” means the net earnings from self-employment (as defined in section 1402(a)), but such net earnings shall be determined—
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(v)WITH REGARD [emphasis added] to the deductions allowed by section 404 to the taxpayer, and
(vi)WITH REGARD [emphasis added] to the deduction allowed to the taxpayer by section 164(f).

This is understood to mean that before calculating the SEP-IRA, Keogh Plan or SIMPLE IRA contribution for a self-employed person, his net profit from business is reduced by:

(vi) one-half the self-employment tax, and
(v) by 3/103 for the employer contribution, in the case of a SIMPLE IRA or by 25/125 (formerly 15/115) for the employer contribution, in the case of a SEP-IRA or Keogh Plan before calculating the contribution or deferral.

Section 408(p)(6)(A)(ii) provides that:

In the case of an employee described in subparagraph (B), the term “compensation” means net earnings from self-employment determined under section 1402(a) WITHOUT REGARD [emphasis added] to any contribution under this subsection. The preceding sentence shall be applied as if the term “trade or business” for purposes of section 1402 included service described in section 1402(c)(6).

(B) Employee
The term “employee” includes an employee as defined in section 401(c)(1).

Can someone explain the meaning of and difference between “determined with regard” and “determined without regard” for calculating SEP-IRA, Keogh Plan or SIMPLE IRA deductions for self-employed persons? It would be a lot easier if the Code had language like “determined without reducing by” or “determined by first reducing by.”

Thanks in advance.