1 files changed, 1 insertions, 0 deletions
diff --git a/apl9.h b/apl9.h
index 2b61a3d..d4e054d 100644
--- a/apl9.h
+++ b/apl9.h
@@ -269,6 +269,7 @@ Array *opSwitch(Datum *, Array *, Array *);
 
 /* Dyadic operators from operators.c */
 Array *opBind(Datum *, Datum *, Array *, Array *);
+Array *opAtop(Datum *, Datum *, Array *, Array *);
 Array *opOver(Datum *, Datum *, Array *, Array *);
 
 /* Dyadic functions from hybrids.c */