Variables with the same name

Hi,

Here's something that causes confusion ... (% comments by me)

 [eclipse 4]: read(T1),read(T2),write(T1),write(' '),write(T2),nl,T1=T2,write(T1),write(' '),write(T2),nl,read(T2),write(T1),write(' '),write(T2),nl.
 f(X,Y).               % Read into T1
 f(g(Y),Z).            % Read into T2
f(X, Y) f(g(Y), Z)     % Echo - yes, they look good
f(g(Y), Y) f(g(Y), Y)  % After unification, but the two Ys are different
 f(T3,b).              % Read into T2
f(g(Y), b) f(g(Y), b)  % Confirmation - the first Y is not instantiated

That's dangerous if the terms are rwitten to a file and read in again - the
two Ys become one. I tried to use write_term/2 with the variables(full) 
option, but ...

 [eclipse 5]: write_term(p(X),[variables(full)]).
calling an undefined procedure write_term(p(X), [variables(full)]) in module eclipse
Abort

I'm using ...
    ECLiPSe Constraint Logic Programming System [kernel]
    Copyright Imperial College London and ICL
    Certain libraries copyright Parc Technologies Ltd
    GMP library copyright Free Software Foundation
    Version 5.2 #10, Tue Jun 26 02:14 2001

Any suggestions out there?

Cheers,

Geoff

Geoff Sutcliffe                           http://www.cs.miami.edu/~geoff
Department of Computer Science            Email : geoff@cs.miami.edu
University of Miami                       Phone : +1 305 2842158/2842268
(Director of Undergraduate Studies)       FAX   : +1 305 2842264