Wrong spacing when operators followed by super-or-subscripts

[RadioNoiseE]

Hi.

The desired behavior of something like \lambda x.M=_\alpha\lambda y.M^{x\rightarrow y} should have no extra spacing inserted between the $=$ (equivalent sign) and the $_\alpha$ (alpha as subscript).

However the (relevant) MathML output of BlahTeXML is:

<msub>
  <mo lspace="0.278em" rspace="0.278em">=</mo>
  <mi>α</mi>
</msub>

which renders like this:

[gvanas]

Hello, this looks like a valid issue, but I don't have the bandwidth to work on blahtexml anymore. Pull requests are welcome, as well as any volunteers who wishes to work actively on this. :-)