I'm guessing nobody knows how closed/open intervals work.
?
In that one includes the boundaries on the interval, and the other doesn't. I doubt anybody in my class notices fine detail like that. I'm at UC Davis, not MIT. I proved it yesterday when I told a friend what happened and I got back a "that matters?!"
I'll text her today. So you can all enjoy my humiliation when I find out she's less pretty than I remember. :p