Display:

$\exists x\colon f(x)=0$

Source:

<apply>
     <exists/>
     <bvar>
          <ci> x </ci>
     </bvar>
     <apply>
          <eq/>
          <apply>
               <fn>
                    <ci> f </ci>
               </fn>
               <ci> x </ci>
          </apply>
          <cn>0</cn>
     </apply>
</apply>