"@Char dropped (character "n" unknown in font Symbol Base)"

Hello,

I used

  @E { a sub {@Sym nu} = 1 }

and got the err-message "@Char dropped (character "n" unknown in font  
Symbol Base)".

It seems, that the fonts for greek letters are *not* coming together with
lout(?!) even though the @Sym command refers to them.

1) How to get greek letters in lout, if that font is not installed.
2) What's the official name of that font?
3) How to get the needed font for Linux (especially Arch Linux)?

Is this a font-issue at all?

I used:
@SysInclude { math  }
@SysInclude { diag  }
@SysInclude { eq  }
@SysInclude { tbl }
maybe other Includes would help to fix the problem?

Ciao,
    Oliver