I need to show that if sup A < sup B, then there is an element in B that is an upper bound of A.(adsbygoogle = window.adsbygoogle || []).push({});

Well I know that if sup B is in B, then sub B is the element in B that is an upper bound of A. But I don't know how to show this is true if sup B is not in B.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Suprema and Infima

**Physics Forums | Science Articles, Homework Help, Discussion**