Input tax credit verification - assessing authority must ensure statutory conditions before allowing credit; certain proportionate reductions excluded. Assessing authorities must verify compliance with conditions for allowance of input tax credit, including clause (g) of section 9(2). Section 10(5)'s proportionate reduction does not apply where goods are sold at a loss in the ordinary course or where a selling dealer issues a credit note post invoice for discounts or incentives; similarly, sales at administered prices by specified oil companies are excluded from section 10(5).