FIXED: meta_predicate/1 declaration of (',')/3 and (;)/3.
:- use_module(library(dif)).
-:- meta_predicate if_(1, 0, 0).
+:- meta_predicate(if_(1, 0, 0)).
if_(If_1, Then_0, Else_0) :-
call(If_1, T),
@@ -50,12 +50,12 @@ i_tpartition([X|Xs], P_2, Ts0, Fs0) :-
, ( Fs0 = [X|Fs], Ts0 = Ts ) ),
i_tpartition(Xs, P_2, Ts, Fs).
-:- meta_predicate ','(0, 0, ?).
+:- meta_predicate(','(1, 1, ?)).
','(A_1, B_1, T) :-
if_(A_1, call(B_1, T), T = false).
-:- meta_predicate ';'(0, 0, ?).
+:- meta_predicate(';'(1, 1, ?)).
';'(A_1, B_1, T) :-
if_(A_1, T = true, call(B_1, T)).
