p(1..2).

%
% #domain-declarations are REQUIRED
% for variables that are used in the
% names of cr-rules.
%
#domain p(X).

r1(X): a(X) +-.


ok :- a(X).
:- not ok.

prefer(r1(1),r1(2)).


% pretty-print the output
%
#hide prefer(A,B).
#hide p(A).
#hide ok.