My logic prof told me that "some are" does NOT necessarily mean "some are not".... Ie. it could possibly mean "ALL are", but not necessarily (ie. we are not certain that all are) However, recently I was reading a book that was using Aristotelian logic and they said that "some are" entails "some are not". My former logic prof wrote this off as a careless/uninformed error. But is it in fact a difference in classical/modern definitions?
I tried to google search this, but couldn't find a clear answer.