Unabsorbed losses carryforward under MAT allowed despite book profit computation; companies must furnish CA certificate Form 29B with returns. Companies subject to Minimum Alternate Tax remain entitled to determine and carry forward unabsorbed depreciation and specified losses for set off under normal income tax provisions despite tax computation on book profits; such companies must file a Chartered Accountant's certificate in the prescribed Form 29B certifying correct computation of book profits along with the income tax return filed under the Act or in response to a statutory notice.