In some ways it's difficult to provide a lot of specifics for that kind of analysis.
Clearly, if the U.S. did withdraw from NAFTA, Canada and the U.S. would probably continue to be each other's largest trading partner, just because of the fundamental economics around that. In all likelihood that trade would become more expensive. If the U.S. did withdraw from NAFTA and started to reimpose some tariffs against imports coming from Canada, then we would anticipate some adjustment in currencies to reflect those additional costs. Certainly we'd be looking at domestic policies to ensure that our industries would remain competitive.
I think assessing an impact in the absence of knowing what measures may be taken or what some of the unpredictable factors might be is very difficult as a definitive prediction.