s="op">-</span> <span class="va">b</span><span class="op">[</span><span class="va">ii</span>,<span class="fl">2</span><span class="op">]</span>  <span class="op">)</span> <span class="op">)</span><span class="op">^</span><span class="va">Q</span><span class="op">[</span><span class="va">ii</span>,<span class="fl">2</span><span class="op">]</span></span>
<span>            <span class="op">}</span></span>
<span><span class="va">dat</span><span class="op">[</span> <span class="va">prob</span> <span class="op">