(2)Where any building, machinery, plant or furniture is not exclusively used for the purposes of the business or profession, the deductions under sub-clause (ii) of clause (a) and clause (c) of section 30, clauses (i) and (ii) of section 31 and [clause (ii) of sub-section (1)] [ Substituted by Act 46 of 1986, Section 32, for certain words (w.e.f. 1.4.1988).] of section 32 shall be restricted to a fair proportionate part thereof which the [Assessing Officer] [ Substituted by Act 4 of 1988, Section 2, for " Income-tax Officer" (w.e.f. 1.4.1988).] may determine, having regard to the user of such building, machinery, plant or furniture for the purposes of the business or profession.
