:- import tfindall/3, abolish_table_pred/1 from tables.
:- import numbervars/3 from num_vars.

:- table b/2.
:- table q/2.

testcombo :-	(a4w(_,_,_),fail ;
		 abolish_table_pred(b/2),a5w(_,_,_),fail ;
		 abolish_table_pred(b/2),a6w(_,_,_),fail).

a4w(A,B,C) :- a4(A,B,C),T = a4(A,B,C),numbervars(T,0,_T1),writeq(T),nl.

a5w(A,B,C) :- a5(A,B,C),T = a5(A,B,C),numbervars(T,0,_T1),writeq(T),nl.

a6w(A,B,C) :- a6(A,B,C),T = a6(A,B,C),numbervars(T,0,_T1),writeq(T),nl.

a4(_A,_B,L) :- b(X,Y), tfindall(X-Y,b(X,Y),L1), sort(L1,L).

a5(X,Y,L) :- b(X,Y), tfindall(X-Y,b(X,Y),L1), sort(L1,L).

a6(X,Y,L) :- q(X,Y), tfindall(X-Y,q(X,Y),L1), sort(L1,L).

b(X,Y) :- p(X,Y).
b(_,_).

p(1,2).
p(1,3).
p(2,3).

q(1,2).
q(1,3).
q(2,3).