IFRS 2 ( Equity Based Settlement)

1. For MODIFICATION of equity based settlement, if the “FV of the ORIGINAL equity instrument” larger than the “FV of NEW equity instrument”, the standard say the original FV of the equity instrument should be expensed as IF the modification NEVER OCCURRED. What does this mean? Is it we can ignore the modification and expense as usual? If yes, what is the reason? As a transaction is already occurred, how can we ignore it?