\usepackage{oz, amsfonts} \begin{schema}{MusicStore} member: \pset NAME\\ orders: \pset (NAME\times ALBUM)\\ owns: \pset (NAME\times ALBUM) \ST {\bf dom}\mbox{ } orders \subseteq member\\ {\bf dom}\mbox{ } owns \subseteq member\\ \forall (m, a)\in orders.(m, a)\notin owns \end{schema}