from lars hellström re greek in math:
Allowing greek letters does however raise some interesting problems. Many
of the greek letters have var-forms in the current math fonts, so which
form should the input letter select? E.g. \epsilon and \varepsilon are
hardly distinct enough to count as different letters/symbols, they are
merely different glyphs, so which one should it be? I for one much prefer
\varepsilon, so I would like to have some interface which lets the user
in fact all the variant greek letters (that i am familiar with)
*do* have distinct unicodes. the problem of how they'll actually
be used still remains.
i'd also like to point out that there text strings can legitimately
be embedded in math expressions, and math can be embedded in those
text strings ... (i don't think i've seen any deeper nesting in the
wild, but such could be invented), so the transitions do have to
be taken into account.