I was going to say all, but I should be careful not to do that. I think it's certainly the case that at least most of our tax treaties and their implementation legislation provide that their terms are to apply or to prevail over any other inconsistent legislation. It's not my understanding—and I'm offering an amateur opinion here—that it extends to override constitutional law or the like. What it does is intend to override other domestic tax rules that would be inconsistent with the tax treaty.
On May 29th, 2014. See this statement in context.