Hi everybody! I have started working through Spivak's "Calculus". I was slightly upset with the first chapter. The book made a few assumptions. (The concept of a number and that if a=b then a+c=b+c, stuff like that) I am fine with it for now because I know where the gap in knowledge is but when I get further in the book, I won't be able to recognize things like that. I was wondering if the book kept assuming things like that later in the book? Thank you for your time!