Sorry, what do you mean? What's an `N-1'? My point was that humans don't offer any 100% guarantees either. However, an argument based on shades of grey, rath

Sorry, what do you mean? What's an `N-1'? My point was that humans don't offer any 100% guarantees either. However, an argument based on shades of grey, rather than binary absolutes, would obviously still work.