       |</span></span></span>
<span class="r-in"><span><span class="co">#  |---|     |          |---|     |</span></span></span>
<span class="r-in"><span><span class="co"># AA   AB    BA        AA   AB    BA</span></span></span>
<span class="r-in"><span><span class="va">A</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/matrix.html" class="external-link">matrix</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-lin