fof(pXY,question, ? [X,Y] : p(X,Y) ).
SZS answers short for ANS001+1 [[a,b],[b,Z],[a,c]]
SZS answers start for ANS001+1
fof(1,answer,
? [X,Y] :
( X = a & Y = b & p(X,Y) ),
answer_to(pXY,[])).
fof(2,answer,
? [X,Y] :
( X = b & Y = Z & p(X,Y) ),
answer_to(pXY,[])).
fof(3,answer,
? [X,Y] :
( X = a & Y = c & p(X,Y) ),
answer_to(pXY,[])).
SZS answers end for ANS001+1