an class="mord mtight" style=""><span class="mord mathnormal mtight" style="">d</span><span class="mord mathnormal mtight" style="">a</span><span class="mord mathnormal mtight" style="">t</span><span class="mord mathnormal mtight" style="">a</span></span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span><span class="mopen" style="">(</span><span class="mord" style=""><span class=