fix attributed variables bug causing weighted_maximum/3 example to omit a variable binding

src/prolog/lib/clpb.pl

@@ -1159,7 +1159,7 @@ labeling_var(V) :- V == 1, !.
 labeling_var(V) :- domain_error(clpb_variable, V).
 
 variables_in_index_order(Vs0, Vs) :-
-        maplist(var_with_index, Vs0, IVs0),
+        maplist(var_with_index, Vs0, IVs0),	
         keysort(IVs0, IVs),
         pairs_values(IVs, Vs).
 
@@ -1245,7 +1245,7 @@ bdd_count(Node, VNum, Count) :-
                 bdd_pow(Low, V, VNum, LPow),
                 bdd_pow(High, V, VNum, HPow),
                 Count0 is LPow*LCount + HPow*HCount,
-                Count = Count0
+		Count0 = Count
             )
         ).
 
@@ -1358,7 +1358,7 @@ weighted_maximum(Ws, Vars, Max) :-
         pairs_values(IVs1, VarsIndexOrder),
         % Pairs is a list of Var-Weight terms, in index order of Vars
         pairs_keys_values(Pairs, VarsIndexOrder, WeightsIndexOrder),
-        bdd_maximum(BDD, Pairs, Max),
+        bdd_maximum(BDD, Pairs, Max), %% A,B are in BDD, but not C; A,B,C *are* in Pairs.
         max_labeling(BDD, Pairs).
 
 max_labeling(1, Pairs) :- max_upto(Pairs, _, _).
@@ -1509,7 +1509,7 @@ max_variable_node(Node, V0-N0, V-N) :-
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
 ands_fusion(Ands0, Ands) :-
-        maplist(with_variables, Ands0, Pairs0),
+        maplist(with_variables, Ands0, Pairs0),	
         keysort(Pairs0, Pairs),
         group_pairs_by_key(Pairs, Groups),
         pairs_values(Groups, Andss),

src/prolog/lib/dif.pl

@@ -51,4 +51,5 @@ gather_dif_goals([(X \== Y) | Goals]) -->
 
 attribute_goals(X) -->
     { get_atts(X, +dif(Goals)) },
-    gather_dif_goals(Goals).
+    gather_dif_goals(Goals),
+    { put_atts(X, -dif(_)) }.

src/prolog/lib/freeze.pl

@@ -26,6 +26,7 @@ gather_freeze_goals(Attrs, _) -->
     !.
 gather_freeze_goals([frozen(X) | _], Var) -->
     [freeze(Var, X)],
+    { put_atts(Var, -frozen(_)) },
     !.
 gather_freeze_goals([_ | Attrs], Var) -->
     gather_freeze_goals(Attrs, Var).

src/prolog/lib/lists.pl

@@ -3,6 +3,7 @@
 		  maplist/4, maplist/5, maplist/6, maplist/7,
 		  maplist/8, maplist/9]).
 
+
 length(Xs, N) :-
     var(N), !,
     '$skip_max_list'(M, -1, Xs, Xs0),
@@ -30,17 +31,22 @@ length_rundown([_|Xs], N) :-
     N1 is N-1,
     length_rundown(Xs, N1).
 
+
 member(X, [X|_]).
 member(X, [_|Xs]) :- member(X, Xs).
 
+
 select(X, [X|Xs], Xs).
 select(X, [Y|Xs], [Y|Ys]) :- select(X, Xs, Ys).
 
+
 append([], R, R).
 append([X|L], R, [X|S]) :- append(L, R, S).
 
+
 memberchk(X, Xs) :- member(X, Xs), !.
 
+
 reverse(Xs, Ys) :-
     (  nonvar(Xs) -> reverse(Xs, Ys, [], Xs)
     ;  reverse(Ys, Xs, [], Ys)
@@ -50,6 +56,7 @@ reverse([], [], YsRev, YsRev).
 reverse([X1|Xs], [Y1|Ys], YsPreludeRev, Xss) :-
     reverse(Xs, Ys, [Y1|YsPreludeRev], Xss).
 
+
 maplist(_, []).
 maplist(Cont1, [E1|E1s]) :-
     call(Cont1, E1),