Hi Volker,
> The symbol you are looking for is present in the PostScript "Symbol"
> font as "element" (PostScript name), and can be acessed in the groff
> symbol set ("S") as "mo" (groff name, standing for "member of").
You can find out it's \(mo by either looking at the Special Character
Names on the last page of CSTR 54, http://troff.org/54.pdf, or do what I
initial did on finding out LaTeX's \in was U+2208, ∈, examine
groff_char(7).
$ man groff_char | sed -n '/^ *Output/{N;h}; /∈/{x;G;p;q}'
Output Input PostScript Unicode Notes
name name decomposed
∈ \[mo] element u2208 +
$
Cheers, Ralph.
