1 files changed, 1 insertions, 0 deletions
diff --git a/lib.h b/lib.h
index 6d706b3d..08e7acb2 100644
--- a/lib.h
+++ b/lib.h
@@ -1078,6 +1078,7 @@ val drop_while(val pred, val seq, val keyfun);
 val drop_until(val pred, val seq, val keyfun);
 val in(val seq, val key, val testfun, val keyfun);
 val set_diff(val list1, val list2, val testfun, val keyfun);
+val diff(val seq1, val seq2, val testfun, val keyfun);
 val isec(val list1, val list2, val testfun, val keyfun);
 val uni(val list1, val list2, val testfun, val keyfun);
 val copy(val seq);