delimited by a box and shown in Figure \[fig:f4\]. In this case, the symbolic description of $K$ follows from the substitution $K=\sigma(H)$, where $\sigma$ is defined as $$\sigma(a) =
\begin{pmatrix}
  r & w & r & w & r & w & r & w \\
  w & r & w & r & w & r & w & w \\
  r & w & r & w & r & w & r & w \\
  w & w & w & w & w & w & w & w
\end{pmatrix},$$ $$\sigma(\bar{a}) =
\begin{pmatrix}
  w & r & w & r & w & r & w & w \\
  r & w & r & w & r & w & r & w \\
  w & r & w & r & w & r & w & w \\
  w & w & w & w & w & w & w & w
\end{pmatrix},$$ $$\sigma(b) =
\begin{pmatrix}
  w & b & w & b & w & b & w & w \\
  b & w & b & w & b & w & b & w \\
  w & b & 