From 87abcd6a5252ff809d6b598677006786046df754 Mon Sep 17 00:00:00 2001
From: Markus Triska <triska@metalevel.at>
Date: Fri, 5 Mar 2021 18:16:38 +0100
Subject: [PATCH 1/3] adapt comment to Scryer Prolog

---
 src/lib/clpb.pl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/lib/clpb.pl b/src/lib/clpb.pl
index 75a38282..add580ff 100644
--- a/src/lib/clpb.pl
+++ b/src/lib/clpb.pl
@@ -1517,8 +1517,8 @@ pairs_([], _) --> [].
 pairs_([B|Bs], A) --> [A-B], pairs_(Bs, A).
 
 /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-   Set the Prolog flag clpb_residuals to bdd to obtain the BDD nodes
-   as residuals. Note that they cannot be used as regular goals.
+   Assert clpb:clpb_residuals(bdd) to obtain the BDD nodes as
+   residuals. Note that they cannot be used as regular goals.
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
 nodes([]) --> [].

From 0fb74b56b378b3518bb1201099c3953ad677a8d2 Mon Sep 17 00:00:00 2001
From: Markus Triska <triska@metalevel.at>
Date: Fri, 5 Mar 2021 18:35:19 +0100
Subject: [PATCH 2/3] FIXED: CLP(B): weighted_maximum/3 with repeated variables

Many thanks to @jburse for reporting this issue:

    https://github.com/triska/clpz/issues/15

Example:

    ?- sat(~(Y*X)), sat(Z=:=Y), weighted_maximum([7,2,5],[X,Y,Z],W).
       W = 7, Y = 0, X = 1, Z = 0
    ;  W = 7, Y = 1, X = 0, Z = 1
    ;  false.
---
 src/lib/clpb.pl | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/lib/clpb.pl b/src/lib/clpb.pl
index add580ff..f41e2100 100644
--- a/src/lib/clpb.pl
+++ b/src/lib/clpb.pl
@@ -1276,13 +1276,18 @@ weighted_maximum(Ws, Vars, Max) :-
         maplist(var_with_index, Vars, IVs),
         pairs_keys_values(Pairs0, IVs, Ws),
         keysort(Pairs0, Pairs1),
-        pairs_keys_values(Pairs1, IVs1, WeightsIndexOrder),
+        % sum linear combinations of repeated variables
+        group_pairs_by_key(Pairs1, Groups),
+        maplist(group_sumweights_pair, Groups, Pairs2),
+        pairs_keys_values(Pairs2, IVs1, WeightsIndexOrder),
         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),
         max_labeling(BDD, Pairs).
 
+group_sumweights_pair((I-V)-Ws, (I-V)-W) :- sum_list(Ws, W).
+
 max_labeling(1, Pairs) :- max_upto(Pairs, _, _).
 max_labeling(node(_,Var,Low,High,Aux), Pairs0) :-
         max_upto(Pairs0, Var, Pairs),

From 842176a595c4fa151f5fe9ec41826dbae52c0390 Mon Sep 17 00:00:00 2001
From: Markus Triska <triska@metalevel.at>
Date: Fri, 5 Mar 2021 18:36:00 +0100
Subject: [PATCH 3/3] is is --> is

---
 src/lib/format.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/format.pl b/src/lib/format.pl
index 823c700c..d873f2cc 100644
--- a/src/lib/format.pl
+++ b/src/lib/format.pl
@@ -153,7 +153,7 @@ element_gluevar(glue(_,V), N, N) --> [V].
    available space is distributed.
 
    newline is used if ~n occurs in a format string.
-   It is is used because a newline character does not
+   It is used because a newline character does not
    consume whitespace in the sense of format strings.
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */