Darien

Yeah, I didn't see the value either in that chapter, but here it is: It uses put-call parity to explain the credit risks of equity and bond holders in a company.

Equity (or stock) is equal to a call bought on the assets (A) with face value of liabilities or bonds (F) as strike price.

MV Bond is equal to default-free bond plus a put written on the assets (A) and with the face value of liabilities or bonds (F) as strike price.

Work out the payouts and you will see that's correct.