<dictionary>
 <operator name="&#x2032;" form="infix" stretchy="false" lspace="0em" rspace="0em"/> <!-- prime -->
 <operator name="&#x2033;" form="infix" stretchy="false" lspace="0em" rspace="0em"/> <!-- Prime -->

 <operator name="&#x2212;" form="prefix" lspace="0em" rspace="veryverythinmathspace"/> <!-- minus -->
 <operator name="&#x2212;" form="infix" lspace="mediummathspace" rspace="mediummathspace"/>

 <!-- the following, IMHO, is the real overline char -->
 <operator name="&#x0305;" form="infix" stretchy="true" lspace="0em" rspace="0em" accent="false"/>

 <operator name="/" form="infix" stretchy="false" lspace="veryverythinmathspace" rspace="veryverythinmathspace"/>
 
 <operator name="&#x221a;" form="prefix" stretchy="false" symmetric="false"/> <!-- Sqrt -->

 <operator name="&#x2146;" form="prefix" lspace="0em" rspace="0em"/> <!-- dd -->
 <operator name="&#x2145;" form="prefix" lspace="0em" rspace="0em"/> <!-- DD -->
 <operator name="&#x2022;" form="prefix" lspace="0em" rspace="0em"/> <!-- PartialD -->

 <!-- || is stretchy -->
 <operator name="&#x2225;" form="infix" stretchy="true" lspace="thickmathspace" rspace="thickmathspace"/>
 <operator name="&#x2223;" form="infix" stretchy="true" lspace="thickmathspace" rspace="thickmathspace"/>
</dictionary>