1 files changed, 2 insertions, 2 deletions
diff --git a/extra.lisp b/extra.lisp
index 67d057c..4a67d84 100644
--- a/extra.lisp
+++ b/extra.lisp
@@ -51,8 +51,8 @@
                nothing)))
         (cons v vn)))
 
-(defun surrounded (p left right)
+(defun surrounded (p left &optional right)
   (comp ((_ left)
          (body p)
-         (_ right))
+         (_ (or right left)))
         body))