1. The problem statement, all variables and given/known data Find the supremum of E=(0,1) 2. Relevant equations 3. The attempt at a solution By definition of open interval, x<1 for all x in E. So 1 is an upper bound. Let M be any upper bound. We must show [tex]1<=M[/tex]. Can I just say that any upper bound of M must be greater than or equal to one based on the definition of open interval again? I'm just not sure if that last line is completely correct. Thanks.