\begin{frame} \frametitle{Degree of a Relationship Set} \begin{center} \scalebox{.9}{ \begin{tikzpicture}[every edge/.style={link}] \node[entity] (A) {A}; \node[entity,right of=A, node distance=6cm] (B) {B}; \node[entity,right of=A, node distance=3cm,yshift=2cm] (C) {C}; \node[relationship,scale=.9,minimum size=10mm] at ($(A)!.5!(B)$) {R} edge (A) edge (B) edge (C); \end{tikzpicture}} \end{center} \begin{goal}{} Non-binary relationship sets can be represented using binary ones by creating an artificial entity set. \end{goal} \begin{center} \scalebox{.9}{ \begin{tikzpicture}[every edge/.style={link}] \node[entity] (A) {A}; \node[entity,right of=A, node distance=6cm] (B) {B}; \node[entity,right of=A, node distance=3cm,yshift=2.5cm] (C) {C}; \node[entity,minimum size=10mm] at ($(A)!.5!(B)$) (E) {E}; \node[relationship,scale=.9,minimum size=10mm] at ($(A)!.5!(E)$) {R$_A$} edge (A) edge (E); \node[relationship,scale=.9,minimum size=10mm] at ($(B)!.5!(E)$) {R$_B$} edge (B) edge (E); \node[relationship,scale=.9,minimum size=10mm] at ($(C)!.5!(E)$) {R$_C$} edge (C) edge (E); \end{tikzpicture}} \end{center} \end{frame}