I want to use \varpi in normal font and \varpiup from txfonts.
I don't want to change the font for general text.
I have read quickly the following answers, but I don't understand and don't know how to use them for my purpose.
A further question arise : How if I want to use the two different \varpi both
in normal font and in txfonts? I guess I need to create a new command like \varpitxfonts?
In general, how to use, in the same time, some characters or symbols that have the same names in more than one fonts?
