--- a/lib/ur/monad.urs	Sat May 15 12:52:34 2010 -0400
+++ b/lib/ur/monad.urs	Sun May 16 15:34:24 2010 -0400
@@ -60,3 +60,10 @@
                    tf t -> tr rest -> m (tf' t * tr ([nm = t] ++ rest)))
                -> tr []
                -> r ::: {K} -> folder r -> $(map tf r) -> m ($(map tf' r) * tr r)
+
+val appR2 : K --> m ::: (Type -> Type) -> monad m
+             -> tf1 :: (K -> Type) -> tf2 :: (K -> Type)
+             -> (nm :: Name -> t :: K -> rest :: {K}
+                 -> [[nm] ~ rest] =>
+                       tf1 t -> tf2 t -> m unit)
+             -> r ::: {K} -> folder r -> $(map tf1 r) -> $(map tf2 r) -> m unit