add mvth to mmil.html (#4996)

Author: jkingdon

mmil.raw.html

@@ -14110,6 +14110,15 @@
   <td>the set.mm proof uses dvmptres and dvmptco</td>
 </tr>
 
+<tr>
+  <td>mvth</td>
+  <td><i>none</i></td>
+  <td>An argument similar to ~ ivthdich should show impossibility
+  (applying the mean value theorem to the antiderivative of the hover
+  function).  Weaker versions analogous to ~ ivthinc should be
+  possible.</td>
+</tr>
+
 <tr>
   <td>dvle</td>
   <td><i>none</i></td>