According the the mid year report we have a book value of $6.17 (Net Equity of $3.8b, 620m shares)
Its hard to believe that number given the current share price, the response from the IBC presents a good opportunity to justify those numbers and if possible re-evaluate, a re-evaluation could be justified and done in line with falling industry valuations.
The big number driving that unbelievable book value is $3b in goodwill ($2.3b for M2), but im guessing that writedowns of goodwill would be well beyond the mandate the IBC was given.