what wrong with this setof

Hello, 

I changed my clause to this :

display_siblings(X,Y) :- 
     setof(X-Y, (siblings(X,Y), \+X=Y), Sibs),
               member((X-Y,Y), Sibs),
               \+ (Y@<X, member((Y,X), Sibs)).

So I can see how I can change the output of setof.

But now I see only true or false as output.

Roelof

 		 	   		  
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