yes... thats possibly the subject of my homework... anyway, i'm gonna try this... this is the actual assignment: Homework page this are the notes from class: Notes i don't have a book to work from all i have are these notes, which i also have written in my notebook with occassional supplements, but not much. So, i looked at problem 1, i don't know what it means to have B's complement... or to be an interval actually... so i really didn't know where to begin. i know a dedekin cut is like, a point on the number line, and then everything to the left of it? i think... so... i'm not sure what that has to do with anything, except with helping to order the number line... number two, i think i can do, so i'm gonna work on that while someone maybe helps with 1? but thing is, i've never had a notation class like this before... i vaguely know what all the symbols mean, but the proofs and stuff... i'm really struggling, so any pointers also welcome.