[groff] Extra mathematical symbols and emoji

[fdriver]

Hello *roffers,

I recently needed to include the succeeds character - u227B - in an eqn 
equation, e.g.:

n ≻ sqrt n

I don't know of a Groff default font that includes it, but it appears in 
the Symbola font that I installed using Schaffter's install-font.sh. I 
include it in the file with:

.special Symbola

But this doesn't give me the succeeds char (still just the warning 
"can't find special character u227B") and breaks the square root 
overbar, which isn't ideal. In fact, I can't seem to include any 
non-default characters inside an eqn block, even if I can use them in 
the main body.

My compilation command is `groff -me -ek file.me > file.ps', this 
doesn't work with any macro set, or the PDF output.

I suspect I'm doing one (or probably more) of:
- Incorrectly installing fonts.
- Incorrectly loading fonts.
- Misunderstanding eqn/groff fonts.
- Misunderstanding Unicode handling.

My questions:
- How would I use Unicode characters with eqn?
- Is there a way to install a font so that it is used automatically for 
special characters?

Thank you!
Faithfully,
F.Driver