Thank you for the help!  That (i.e., "-@") works!

Minero Aoki <aamine / mx.edit.ne.jp> wrote in message news:<20010928150340X.aamine / mx.edit.ne.jp>...
> Hi,
> 
>   In mail "[ruby-talk:21795] Help: how to (re)define the unary minus?"
>     furufuru / ccsr.u-tokyo.ac.jp (Ryo Furue) wrote:
[...]
> > I'm wondering how one should (re)define the unary minus operator for a
> > class.  The following fails:
>  
> >       def -() # unary???
> >          Complex.new(-@re, -@im)
>  
> >   ./try.rb:17: undefined method `-@' for #<Complex:0xe7f60>
> > (NameError)
> 
> This error message is a hint.

Exactly!  But, I didn't have a slightest idea of what this strange
combination of characters ("-" and "@") meant.

Then I checked the pickaxe book again and found that it describes the
operator in the reference of the Numeric class (p.354).

Thanks again,
Ryo