QUERY:
?- opera(D).

USER PREDICATES:
opera(A) :-
     not home(A).

home(A) :-
     not opera(A).
home(monday).

DUAL RULES:
not opera(A) :-
     not o_opera_1(A).

not o_opera_1(A) :-
     home(A).

not home(A) :-
     not o_home_1(A),
     not o_home_2(A).

not o_home_1(A) :-
     opera(A).

not o_home_2(A) :-
     A \= monday.


GLOBAL CONSTRAINTS:
global_constraint.