On 6/27/2019 6:35 PM, Duncan Hothersall wrote:
> I'm not sure this is something more general in the MathML module or if
> it's specific to the vertical bar in this particular context, but here
> is a minimal example showing that the "=0" at the end of the equation is
> disappearing:

there is indeed some issue, i'll look into it

you can also try

             <mfenced open="(" close=")" separators="|">
               <mi>B</mi>
               <mi>C</mi>