Table 3 Constraint matrices corresponding to the graphs in Figure 7

(a) e₁ = 0/6

$\left[\begin{array}{cccc}1& 0& 0& 0\\ 1& 0& 0\\ 1& 0\\ 1\end{array}\right]$

(b) e₂ = 1/6

$\left[\begin{array}{cccc}1& 1& 0& 0\\ 1& 0& 0\\ 1& 0\\ 1\end{array}\right]$

(c) e₃ = 2/6

$\left[\begin{array}{cccc}1& 1& 0& 0\\ 1& 1& 0\\ 1& 0\\ 1\end{array}\right]$

(d) e₄ = 3/6

$\left[\begin{array}{cccc}1& 1& 0& 0\\ 1& 1& 0\\ 1& 1\\ 1\end{array}\right]$