Solution:

Yes, the put option of X Inc is a financial instrument. It gives X Inc the right, but not the obligation, to sell its identified PPE to Y Inc for $100 million after 3 years. The value of the put option would depend on various factors such as the current market price of the PPE, volatility, time to expiry, and the risk-free interest rate.

Similarly, the written put option of Y Inc is also a financial instrument. It gives Y Inc the obligation to buy the identified PPE from X Inc for $100 million after 3 years, if X Inc chooses to exercise its put option. The value of the written put option would depend on the same factors as the put option of X Inc.

Both the put option and the written put option meet the definition of financial instrument under IAS 32 as they involve a contractual right or obligation to deliver cash or another financial asset. They would need to be recognized and measured at fair value in the financial statements of X Inc and Y Inc, respectively. Any changes in fair value would be recognized in profit or loss or other comprehensive income, depending on the classification of the financial instruments.