Hi, this is an extension that I wanted, awesome.

I tested this in my notes and it works here: ( sorry for Japanese text )
https://github.com/mathmathniconico/Notes/blob/master/Manifold/Tangent.md

but it doesn't work here:
https://github.com/mathmathniconico/Notes/blob/master/ConvergentSpace/Conv.md

So, I think the problem is not just underscore, but '}_' or something.

I hope you will fix this problem, thank you.