S. 71 : Set off of loss-One head against income from another-Constitutional validity and retrospectivity-Set off of loss from one head against income from another Deduction and vested entitlement to set off actual amount of loss-Income from house property to Rs. 2 lakhs for particular assessment year with effect from 1-4-2018-Insertion of sub-section (3A) in section 71 in terms of section 31 d amendment not violative of article 14-Income-tax Act, 1961, s. 71(3A)-Finance Act, 2017, S 31[1], Finance Act, 2017,(2017) 393 ITR (St.) 1) [S. 22,56(2), 71(3A), Art.13, 14, 19(1)(g), 226, 265]