[NTG-context] Which way to type greek letters in synonym list?

Dear All, I am setting up the synonym list. I defined it as "nomenclature" \definesynonyms[nomenclature][nomenclatures][\infull] \setupsynonyms[nomenclature] [criterium=all,location=serried] when i type in someting like \nomenclature{A} {Area} it works. But if I type \nomenclature{$\alpha$}{Angle of something} it fails. The reason may be only text could be used. I found the list is sorted alphabetically. Then if I type a greek letter, the compiler does not konw how to sort it.