--- a/lib/top.urs	Thu Oct 30 17:07:34 2008 -0400
+++ b/lib/top.urs	Fri Oct 31 09:30:22 2008 -0400
@@ -4,6 +4,9 @@
 con record = fn t :: {Type} => $t
 con fstTT = fn t :: (Type * Type) => t.1
 con sndTT = fn t :: (Type * Type) => t.2
+con fstTTT = fn t :: (Type * Type * Type) => t.1
+con sndTTT = fn t :: (Type * Type * Type) => t.2
+con thdTTT = fn t :: (Type * Type * Type) => t.3
 
 con mapTT = fn f :: Type -> Type => fold (fn nm t acc [[nm] ~ acc] =>
                                              [nm = f t] ++ acc) []
@@ -14,6 +17,9 @@
 con mapT2T = fn f :: (Type * Type) -> Type => fold (fn nm t acc [[nm] ~ acc] =>
                                                        [nm = f t] ++ acc) []
 
+con mapT3T = fn f :: (Type * Type * Type) -> Type => fold (fn nm t acc [[nm] ~ acc] =>
+                                                              [nm = f t] ++ acc) []
+
 con ex = fn tf :: (Type -> Type) =>
             res ::: Type -> (choice :: Type -> tf choice -> res) -> res
 
@@ -55,6 +61,12 @@
                         tf t -> tr rest -> tr ([nm = t] ++ rest))
               -> tr [] -> r :: {(Type * Type)} -> $(mapT2T tf r) -> tr r
 
+val foldT3R : tf :: ((Type * Type * Type) -> Type) -> tr :: ({(Type * Type * Type)} -> Type)
+              -> (nm :: Name -> t :: (Type * Type * Type) -> rest :: {(Type * Type * Type)}
+                  -> fn [[nm] ~ rest] =>
+                        tf t -> tr rest -> tr ([nm = t] ++ rest))
+              -> tr [] -> r :: {(Type * Type * Type)} -> $(mapT3T tf r) -> tr r
+
 val foldTR2 : tf1 :: (Type -> Type) -> tf2 :: (Type -> Type)
               -> tr :: ({Type} -> Type)
               -> (nm :: Name -> t :: Type -> rest :: {Type}
@@ -71,6 +83,14 @@
                -> tr [] -> r :: {(Type * Type)}
                -> $(mapT2T tf1 r) -> $(mapT2T tf2 r) -> tr r
 
+val foldT3R2 : tf1 :: ((Type * Type * Type) -> Type) -> tf2 :: ((Type * Type * Type) -> Type)
+               -> tr :: ({(Type * Type * Type)} -> Type)
+               -> (nm :: Name -> t :: (Type * Type * Type) -> rest :: {(Type * Type * Type)}
+                   -> fn [[nm] ~ rest] =>
+                         tf1 t -> tf2 t -> tr rest -> tr ([nm = t] ++ rest))
+               -> tr [] -> r :: {(Type * Type * Type)}
+               -> $(mapT3T tf1 r) -> $(mapT3T tf2 r) -> tr r
+
 val foldTRX : tf :: (Type -> Type) -> ctx :: {Unit}
               -> (nm :: Name -> t :: Type -> rest :: {Type}
                   -> fn [[nm] ~ rest] =>
@@ -83,6 +103,12 @@
                          tf t -> xml ctx [] [])
                -> r :: {(Type * Type)} -> $(mapT2T tf r) -> xml ctx [] []
 
+val foldT3RX : tf :: ((Type * Type * Type) -> Type) -> ctx :: {Unit}
+               -> (nm :: Name -> t :: (Type * Type * Type) -> rest :: {(Type * Type * Type)}
+                   -> fn [[nm] ~ rest] =>
+                         tf t -> xml ctx [] [])
+               -> r :: {(Type * Type * Type)} -> $(mapT3T tf r) -> xml ctx [] []
+
 val foldTRX2 : tf1 :: (Type -> Type) -> tf2 :: (Type -> Type) -> ctx :: {Unit}
                -> (nm :: Name -> t :: Type -> rest :: {Type}
                    -> fn [[nm] ~ rest] =>
@@ -98,6 +124,15 @@
                 -> r :: {(Type * Type)}
                 -> $(mapT2T tf1 r) -> $(mapT2T tf2 r) -> xml ctx [] []
 
+
+val foldT3RX2 : tf1 :: ((Type * Type * Type) -> Type) -> tf2 :: ((Type * Type * Type) -> Type)
+                -> ctx :: {Unit}
+                -> (nm :: Name -> t :: (Type * Type * Type) -> rest :: {(Type * Type * Type)}
+                    -> fn [[nm] ~ rest] =>
+                          tf1 t -> tf2 t -> xml ctx [] [])
+                -> r :: {(Type * Type * Type)}
+                -> $(mapT3T tf1 r) -> $(mapT3T tf2 r) -> xml ctx [] []
+
 val queryX : tables ::: {{Type}} -> exps ::: {Type} -> ctx ::: {Unit}
              -> sql_query tables exps
              -> fn [tables ~ exps] =>