Deduction under Section 32A restricted where Section 32AB claim exists; amendment alters effective dates and notification timing. Amendments to section 32A alter effective commencement dates, substitute Explanation sub clauses setting graduated monetary thresholds for different previous year end periods (deemed effective from an earlier year), omit a three year earliest notification limitation in sub section (8), and insert sub section (8B) providing that, subject to an existing proviso, no deduction under section 32A is allowable where the assessee has claimed the deduction under section 32AB.