How do you account for a subsidiary in a hyperinflationary economy (IAS 29)?

When an economy is hyperinflationary (IAS 29 indicators, notably cumulative inflation approaching or exceeding 100% over three years — currently e.g. Turkey, Argentina), you first restate the subsidiary's financial statements into the measuring unit current at the reporting date before translating. Restatement: non-monetary items (PP&E, inventory, equity) are restated using a general price index from their acquisition/recognition date; monetary items (cash, receivables, payables) are already in current units and aren't restated; the P&L is restated for the change in the index; and the net gain or loss on the net monetary position is recognized in profit or loss. Then you translate the restated statements into the group's presentation currency at the closing rate (all items, including comparatives handling). The practical challenges: obtaining reliable price indices, the closing-rate translation of restated figures, and that comparatives are generally not restated for the index when the presentation currency is non-hyperinflationary. It's an area auditors and groups find operationally hard.