<span class="r-out co"><span class="r-pr">#&gt;</span>      X0Y0 X1Y0 X0Y1 X1Y1</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> X.0     1    0    1    0</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> X.1     0    1    0    1</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Y.00    1    1    0    0</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Y.10    0    1    1    0</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Y.01    1    0    0   