For $\Omega = [-30, 30]\times [-30, 30]$, the associated continuous pattern $B$ is shown in Figure \[fig:f2\]. A box delimits the elementary $6 \times 10$ discrete pattern $F$ that can describe $B$ by successive substitutions, viz. $$F = \begin{pmatrix}
  b & w & b & w & b & w \\
  r & w & r & w & r & w \\
  b & r & b & r & b & r \\
  r & b & r & b & r & b \\
  w & r & w & r & w & r \\
  w & b & w & b & w & b \\
  w & r & w & r & w & r \\
  r & b & r & b & r & b \\
  b & r & b & r & b & r \\
  r & w & r & w & r & w
\end{pmatrix}.$$

This discrete pattern can be decomposed as $$\sigma(f) = 
{}^t\begin{pmatrix}
  w & w & r & b & r & b & r & b & r & w \\
  b & r & b & r & w & w 