ic: stronger propagation possible?

Dear all,

the following does not find the sole solution X=2 and Y=2, but an
additional labeling does.

[eclipse 1]: lib(ic), [X,Y] :: 1..2, neg(X#=1 and Y#=1), neg (X#=1 and Y#=2), neg(X#=2 and Y#=1).

X = X{[1, 2]}
Y = Y{[1, 2]}

There are 9 delayed goals. Do you want to see them? (y/n)

...

[eclipse 2]: [X,Y] :: 1..2, neg(X#=1 and Y#=1), neg (X#=1 and Y#=2), neg(X#=2 and Y#=1), labeling([X,Y]).

X = 2
Y = 2
Yes (0.00s cpu)


How can I get such a stronger result for a list of variables without
having to search for their instantiations?  In other words, can I
achieve stronger propagation?

Thank you, Uli

-- 
Ulrich Scholz

scholz@informatik.tu-darmstadt.de
http://www.intellektik.informatik.tu-darmstadt.de/~scholz