</span><span class="base"><span class="strut" style="height:0.84444em;vertical-align:-0.15em;"></span><span class="mord coloredeq eqk" style=""><span class="mord" style=""><span class="mord mathnormal" style="margin-right:0.03785em">δ</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.2805559999999999em;"><span style="top:-2.5500000000000003em;margin-left:-0.03785em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><spa