\begin{exercice}
 Construire un patron de ce cube et y reporter les motifs sur chacune des faces. 
\begin{center}
\begin{tikzpicture}[general, scale=0.8]
  \draw (0,0)--(3,0)--(3,3)--(0,3)--cycle;
  \draw (0,3)--(2,4)--(5,4)--(3,3);
  \draw (5,4)--(5,1)--(3,0);
  \draw[ dashed] (2,4)--(2,1)--(5,1);
  \draw[ dashed] (0,0)--(2,1);
  \draw (1.5,1.5) node {{\LARGE \boldmath $\nabla$}};
  \draw (4,2) node {{\LARGE \rotatebox{30.0}{$\partial$}}};
  \draw (2.5,3.5) node {{\LARGE \rotatebox{-30.0}{$\forall$}}};
  \draw[color=F1] (1,2) node {{\LARGE \rotatebox{30.0}{$\infty$}}};
  \draw[color=F1] (2.5,0.5) node {{\LARGE \rotatebox{-50.0}{$\exists$}}};
  \draw[color=F1] (3.5,2.5) node {{\LARGE \boldmath $\varnothing$}};
 \end{tikzpicture}
 \end{center}
{\it Les motifs noirs sont sur des faces visibles et les motifs rouges sur des faces non visibles.}
\end{exercice}
