1 files changed, 19 insertions, 0 deletions
diff --git a/prolog/problems/sets/diff_3/common.py b/prolog/problems/sets/diff_3/common.py
new file mode 100644
index 0000000..76b88ed
--- /dev/null
+++ b/prolog/problems/sets/diff_3/common.py
@@ -0,0 +1,19 @@
+id = 130
+group = 'sets'
+number = 37
+visible = True
+facts = None
+
+solution = '''\
+memb130(X, [X|_]).
+memb130(X, [_|T]) :-
+  memb130(X, T).
+
+diff([], _, []).
+diff([H|T], S2, [H|D]) :-
+  \+ memb130(H, S2),
+  diff(T, S2, D).
+diff([H|T], S2, D) :-
+  memb130(H, S2),
+  diff(T, S2, D).
+'''