Let's take the example if the variant's collateral value equals to $12,000 and the outstanding NFT value equals to $10,000 ($100 NFT x 100 Units Minted) then the collateral ratio is 120%, the target ratio has been calculated from the given formula to bring the ratio down, presuming that the target ratio is 110% then we have $1,000 to giveaway as a discount, to mint $100 NFT we need to deposit only $100-($1,000x$100/$12,000) = $92.