" class="external-link">c</a></span><span class="op">(</span><span class="fl">1</span>,<span class="fl">1</span>,<span class="fl">1</span>,<span class="fl">1</span>,<span class="fl">2</span>,<span class="fl">2</span>,<span class="fl">2</span>,<span class="fl">2</span>,<span class="fl">3</span>,<span class="fl">4</span>,<span class="fl">3</span>,<span class="fl">4</span><span class="op">)</span><span class="op">)</span>, nrow<span class="op">=</span><span class="fl">4</span><span class="op">)</span></span></