1 files changed, 1 insertions, 0 deletions
diff --git a/apl9.h b/apl9.h
index d7cb4e1..a8d234f 100644
--- a/apl9.h
+++ b/apl9.h
@@ -346,6 +346,7 @@ Array *fnIndex(Array *, Array *);
 Array *fnIndexOf(Array *, Array *);
 Array *fnMembership(Array *, Array *);
 Array *fnUnion(Array *, Array *);
+Array *fnIntersection(Array *, Array *);
 Array *fnExcluding(Array *, Array *);
 Array *fnCatenateLast(Array *, Array *);
 Array *fnCatenateFirst(Array *, Array *);