Example exc-063

Prev: exc-062

Next: exc-064

a b a b ab ba

<math>
<apply><forall/>
  <bvar><ci>a</ci></bvar>
  <bvar><ci>b</ci></bvar>
  <condition>
    <apply><and/>
      <apply><in/><ci>a</ci><reals/></apply>
      <apply><in/><ci>b</ci><reals/></apply>
    </apply>
  </condition>
  <apply><eq/>
    <apply><plus/><ci>a</ci><ci>b</ci></apply>
    <apply><plus/><ci>b</ci><ci>a</ci></apply>
  </apply>
</apply>
</math>