Deduction under section 10A/10B clarifies export-profit deduction and carry forward rules for export-oriented units. Deduction under Section 10A/10B allows export-derived profits of eligible undertakings to be deducted from the assessee's total income for ten consecutive assessment years beginning with production, after computation of income under the Chapter IV heads and aggregation under Chapter VI. Aggregation and set-off rules (sections 70 and 71) apply before the deduction; losses of eligible units for assessment year 2001-02 and later qualify for carry forward and set off under the Act. Amendments effective from 1-4-2001 permit carry forward of business losses and unabsorbed depreciation for SEZ and 100% EOU units.