explicit lhs marks, first step

104 files changed, 577 insertions, 431 deletions

diff --git a/testdata/language-features/basic-list/list01.out b/testdata/language-features/basic-list/list01.out
index 14eb5c08..4a4d6cda 100644
--- a/testdata/language-features/basic-list/list01.out
+++ b/testdata/language-features/basic-list/list01.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs []
+value1 = _lhs value1 (_rhs [])
 
-value2 = _rhs [fromInt 1, fromInt 2, fromInt 3, fromInt 4]
+value2 = _lhs value2 (_rhs [fromInt 1, fromInt 2, fromInt 3, fromInt 4])
 
-value3 = _rhs ['h', 'e', 'l', 'l', 'o']
+value3 = _lhs value3 (_rhs ['h', 'e', 'l', 'l', 'o'])
 ------------ core code
 value1 :: forall a . [a]
 value1 = _rhs []
diff --git a/testdata/language-features/basic-list/list02.out b/testdata/language-features/basic-list/list02.out
index 8710b507..290d0482 100644
--- a/testdata/language-features/basic-list/list02.out
+++ b/testdata/language-features/basic-list/list02.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs []
+value1 = _lhs value1 (_rhs [])
 
-value2 = _rhs [fromInt 1, fromInt 2, fromInt 3, fromInt 4]
+value2 = _lhs value2 (_rhs [fromInt 1, fromInt 2, fromInt 3, fromInt 4])
 
-value3 = _rhs ['h', 'e', 'l', 'l', 'o']
+value3 = _lhs value3 (_rhs ['h', 'e', 'l', 'l', 'o'])
 ------------ core code
 value1 :: forall a . [a]
 value1 = _rhs []
diff --git a/testdata/language-features/basic-list/list08.out b/testdata/language-features/basic-list/list08.out
index e92d9b36..a9ed3391 100644
--- a/testdata/language-features/basic-list/list08.out
+++ b/testdata/language-features/basic-list/list08.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs [fromInt 1, 1.2]
+value = _lhs value (_rhs [fromInt 1, 1.2])
 ------------ core code
 value :: [Float]
 value = _rhs [1.0, 1.2]
diff --git a/testdata/language-features/basic-list/list09.out b/testdata/language-features/basic-list/list09.out
index 676c1ed6..c46fb913 100644
--- a/testdata/language-features/basic-list/list09.out
+++ b/testdata/language-features/basic-list/list09.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs ([fromInt 1, 1.2] :: [Float])
+value = _lhs value (_rhs ([fromInt 1, 1.2] :: [Float]))
 ------------ core code
 value :: [Float]
 value = _rhs [1.0, 1.2]
diff --git a/testdata/language-features/basic-list/list11.out b/testdata/language-features/basic-list/list11.out
index 00b52310..9777fcff 100644
--- a/testdata/language-features/basic-list/list11.out
+++ b/testdata/language-features/basic-list/list11.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs [fromInt 1]
+value = _lhs value (_rhs [fromInt 1])
 ------------ core code
 value :: forall a . Num a => [a]
 value = \a b -> _rhs [fromInt a b 1]
diff --git a/testdata/language-features/basic-list/list12.out b/testdata/language-features/basic-list/list12.out
index 9e289ae6..e8e480be 100644
--- a/testdata/language-features/basic-list/list12.out
+++ b/testdata/language-features/basic-list/list12.out
@@ -1,6 +1,7 @@
 main is not found
 ------------ desugared source code
-value = _rhs [fromInt 1, fromInt 2, fromInt 3, fromInt 4, fromInt 5]
+value
+  = _lhs value (_rhs [fromInt 1, fromInt 2, fromInt 3, fromInt 4, fromInt 5])
 ------------ core code
 value :: forall a . Num a => [a]
 value
diff --git a/testdata/language-features/basic-list/list13.out b/testdata/language-features/basic-list/list13.out
index bb27f13d..c1c89f70 100644
--- a/testdata/language-features/basic-list/list13.out
+++ b/testdata/language-features/basic-list/list13.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs ['h', 'e', 'l', 'l', 'o']
+value = _lhs value (_rhs ['h', 'e', 'l', 'l', 'o'])
 ------------ core code
 value :: [Char]
 value = _rhs ['h', 'e', 'l', 'l', 'o']
diff --git a/testdata/language-features/basic-list/listcomp01.out b/testdata/language-features/basic-list/listcomp01.out
index e02d3045..ace40823 100644
--- a/testdata/language-features/basic-list/listcomp01.out
+++ b/testdata/language-features/basic-list/listcomp01.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs (concatMap (\(_ :: _) -> [()]) [(), (), (), ()])
+value = _lhs value (_rhs (concatMap (\(_ :: _) -> [()]) [(), (), (), ()]))
 ------------ core code
 value :: [()]
 value = _rhs [(), (), (), ()]
diff --git a/testdata/language-features/basic-list/listcomp02.out b/testdata/language-features/basic-list/listcomp02.out
index aa811e16..18619ff6 100644
--- a/testdata/language-features/basic-list/listcomp02.out
+++ b/testdata/language-features/basic-list/listcomp02.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-l = _rhs [(), (), (), ()]
+l = _lhs l (_rhs [(), (), (), ()])
 
-value = _rhs (concatMap (\(a :: _) -> [a]) l)
+value = _lhs value (_rhs (concatMap (\(a :: _) -> [a]) l))
 ------------ core code
 l :: [()]
 l = _rhs [(), (), (), ()]
diff --git a/testdata/language-features/basic-list/listcomp03.out b/testdata/language-features/basic-list/listcomp03.out
index e3192970..0ba6b347 100644
--- a/testdata/language-features/basic-list/listcomp03.out
+++ b/testdata/language-features/basic-list/listcomp03.out
@@ -1,7 +1,9 @@
 main is not found
 ------------ desugared source code
 value
-  = _rhs (concatMap (\(_ :: _) -> primIfThenElse False [()] []) [(), (), (), ()])
+  = _lhs
+    value
+    (_rhs (concatMap (\(_ :: _) -> primIfThenElse False [()] []) [(), (), (), ()]))
 ------------ core code
 value :: [()]
 value = _rhs []
diff --git a/testdata/language-features/basic-list/listcomp04.out b/testdata/language-features/basic-list/listcomp04.out
index 9352d6ae..4d43ac94 100644
--- a/testdata/language-features/basic-list/listcomp04.out
+++ b/testdata/language-features/basic-list/listcomp04.out
@@ -1,8 +1,9 @@
 main is not found
 ------------ desugared source code
-l = _rhs [(), (), (), ()]
+l = _lhs l (_rhs [(), (), (), ()])
 
-value = _rhs (concatMap (\(_ :: _) -> concatMap (\(_ :: _) -> [()]) l) l)
+value
+  = _lhs value (_rhs (concatMap (\(_ :: _) -> concatMap (\(_ :: _) -> [()]) l) l))
 ------------ core code
 l :: [()]
 l = _rhs [(), (), (), ()]
diff --git a/testdata/language-features/basic-list/listcomp05.out b/testdata/language-features/basic-list/listcomp05.out
index c3984bc7..c9e56736 100644
--- a/testdata/language-features/basic-list/listcomp05.out
+++ b/testdata/language-features/basic-list/listcomp05.out
@@ -1,10 +1,14 @@
 main is not found
 ------------ desugared source code
 value
-  = _rhs
-    (concatMap
-      (\(_ :: _) -> let a = _rhs (); b = _rhs ((\(c :: _) -> c) a) in [b])
-      [(), ()])
+  = _lhs
+    value
+    (_rhs
+      (concatMap
+        (\(_ :: _) -> let
+          a = _lhs _u (_rhs ()); b = _lhs u (_rhs ((\(c :: _) -> c) a))
+          in [b])
+        [(), ()]))
 ------------ core code
 value :: [()]
 value = _rhs [(), ()]
diff --git a/testdata/language-features/basic-list/listcomp06.out b/testdata/language-features/basic-list/listcomp06.out
index 3fc12622..cf4e2b31 100644
--- a/testdata/language-features/basic-list/listcomp06.out
+++ b/testdata/language-features/basic-list/listcomp06.out
@@ -1,22 +1,25 @@
 main is not found
 ------------ desugared source code
 value1
-  = _rhs
-    (concatMap
-      (\(_ :: _) -> let a = _rhs (); b = _rhs ((\(c :: _) -> c) a) in primIfThenElse
-        True
-        [b]
-        [])
-      [(), ()])
+  = _lhs
+    value1
+    (_rhs
+      (concatMap
+        (\(_ :: _) -> let
+          a = _lhs _u (_rhs ()); b = _lhs u (_rhs ((\(c :: _) -> c) a))
+          in primIfThenElse True [b] [])
+        [(), ()]))
 
 value2
-  = _rhs
-    (concatMap
-      (\(_ :: _) -> primIfThenElse
-        True
-        (let a = _rhs (); b = _rhs ((\(c :: _) -> c) a) in [b])
-        [])
-      [(), ()])
+  = _lhs
+    value2
+    (_rhs
+      (concatMap
+        (\(_ :: _) -> primIfThenElse
+          True
+          (let a = _lhs _u (_rhs ()); b = _lhs u (_rhs ((\(c :: _) -> c) a)) in [b])
+          [])
+        [(), ()]))
 ------------ core code
 value1 :: [()]
 value1 = _rhs [(), ()]
diff --git a/testdata/language-features/basic-list/listcomp07.out b/testdata/language-features/basic-list/listcomp07.out
index 1923e806..2f4d633a 100644
--- a/testdata/language-features/basic-list/listcomp07.out
+++ b/testdata/language-features/basic-list/listcomp07.out
@@ -1,31 +1,43 @@
 main is not found
 ------------ desugared source code
 value1
-  = _rhs
-    (concatMap
-      (\(_ :: _) -> let a = _rhs (); b = _rhs ((\(c :: _) -> c) a) in primIfThenElse
-        True
-        (let d = _rhs b; e = _rhs ((\(f :: _) -> f) d) in [b])
-        [])
-      [(), ()])
+  = _lhs
+    value1
+    (_rhs
+      (concatMap
+        (\(_ :: _) -> let
+          a = _lhs _u (_rhs ()); b = _lhs u (_rhs ((\(c :: _) -> c) a))
+          in primIfThenElse
+          True
+          (let d = _lhs _v (_rhs b); e = _lhs v (_rhs ((\(f :: _) -> f) d)) in [b])
+          [])
+        [(), ()]))
 
 value2
-  = _rhs
-    (concatMap
-      (\(_ :: _) -> let a = _rhs (); b = _rhs ((\(c :: _) -> c) a) in primIfThenElse
-        True
-        (let d = _rhs b; e = _rhs ((\(f :: _) -> f) d) in [b])
-        [])
-      [(), ()])
+  = _lhs
+    value2
+    (_rhs
+      (concatMap
+        (\(_ :: _) -> let
+          a = _lhs _u (_rhs ()); b = _lhs u (_rhs ((\(c :: _) -> c) a))
+          in primIfThenElse
+          True
+          (let d = _lhs _v (_rhs b); e = _lhs v (_rhs ((\(f :: _) -> f) d)) in [b])
+          [])
+        [(), ()]))
 
 value3
-  = _rhs
-    (concatMap
-      (\(_ :: _) -> let a = _rhs (); b = _rhs ((\(c :: _) -> c) a) in primIfThenElse
-        True
-        (let d = _rhs b; e = _rhs ((\(f :: _) -> f) d) in [b])
-        [])
-      [(), ()])
+  = _lhs
+    value3
+    (_rhs
+      (concatMap
+        (\(_ :: _) -> let
+          a = _lhs _u (_rhs ()); b = _lhs u (_rhs ((\(c :: _) -> c) a))
+          in primIfThenElse
+          True
+          (let d = _lhs _v (_rhs b); e = _lhs v (_rhs ((\(f :: _) -> f) d)) in [b])
+          [])
+        [(), ()]))
 ------------ core code
 value1 :: [()]
 value1 = _rhs [(), ()]
diff --git a/testdata/language-features/basic-list/listcomp09.out b/testdata/language-features/basic-list/listcomp09.out
index b83e6611..6c1c9d6d 100644
--- a/testdata/language-features/basic-list/listcomp09.out
+++ b/testdata/language-features/basic-list/listcomp09.out
@@ -1,7 +1,9 @@
 main is not found
 ------------ desugared source code
 value1
-  = _rhs (concatMap (\(_ :: _) -> [\(a :: _) -> hlistNilCase _ "Hello" a]) [])
+  = _lhs
+    value1
+    (_rhs (concatMap (\(_ :: _) -> [\(a :: _) -> hlistNilCase _ "Hello" a]) []))
 ------------ core code
 value1 :: @Type -> [() -> String]
 value1 = \_ -> _rhs []
diff --git a/testdata/language-features/basic-values/bool01.out b/testdata/language-features/basic-values/bool01.out
index ee5e9859..5d0f35af 100644
--- a/testdata/language-features/basic-values/bool01.out
+++ b/testdata/language-features/basic-values/bool01.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs True
+value1 = _lhs value1 (_rhs True)
 
-value2 = _rhs False
+value2 = _lhs value2 (_rhs False)
 ------------ core code
 value1 :: Bool
 value1 = _rhs True
diff --git a/testdata/language-features/basic-values/case01.out b/testdata/language-features/basic-values/case01.out
index ee13f28e..eff9fb43 100644
--- a/testdata/language-features/basic-values/case01.out
+++ b/testdata/language-features/basic-values/case01.out
@@ -1,16 +1,16 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs ((\(a :: _) -> hlistNilCase _ () a) ())
+value1 = _lhs value1 (_rhs ((\(a :: _) -> hlistNilCase _ () a) ()))
 
-value2 = _rhs ((\(a :: _) -> hlistNilCase _ () a) ())
+value2 = _lhs value2 (_rhs ((\(a :: _) -> hlistNilCase _ () a) ()))
 
-value3 = _rhs ((\(a :: _) -> hlistNilCase _ () a) ())
+value3 = _lhs value3 (_rhs ((\(a :: _) -> hlistNilCase _ () a) ()))
 
-value4 = _rhs ((\(a :: _) -> hlistNilCase _ () a) ())
+value4 = _lhs value4 (_rhs ((\(a :: _) -> hlistNilCase _ () a) ()))
 
-value5 = _rhs ((\(a :: _) -> hlistNilCase _ () a) ())
+value5 = _lhs value5 (_rhs ((\(a :: _) -> hlistNilCase _ () a) ()))
 
-value6 = _rhs ((\(_ :: _) -> ()) ())
+value6 = _lhs value6 (_rhs ((\(_ :: _) -> ()) ()))
 ------------ core code
 value1 :: ()
 value1 = _rhs ()
diff --git a/testdata/language-features/basic-values/case02.out b/testdata/language-features/basic-values/case02.out
index 9d1dd476..f445f91a 100644
--- a/testdata/language-features/basic-values/case02.out
+++ b/testdata/language-features/basic-values/case02.out
@@ -1,17 +1,21 @@
 main is not found
 ------------ desugared source code
 value1
-  = _rhs
-    ((\(a :: _) -> case'Bool (\(_ :: _) -> _) () () (fromInt 1 == a)) (fromInt 1))
+  = _lhs
+    value1
+    (_rhs
+      ((\(a :: _) -> case'Bool (\(_ :: _) -> _) () () (fromInt 1 == a)) (fromInt 1)))
 
 value2
-  = _rhs
-    ((\(a :: _) -> case'Bool
-        (\(_ :: _) -> _)
-        (case'Bool (\(_ :: _) -> _) "_" "2" (fromInt 2 == a))
-        "1"
-        (fromInt 1 == a))
-      (fromInt 2))
+  = _lhs
+    value2
+    (_rhs
+      ((\(a :: _) -> case'Bool
+          (\(_ :: _) -> _)
+          (case'Bool (\(_ :: _) -> _) "_" "2" (fromInt 2 == a))
+          "1"
+          (fromInt 1 == a))
+        (fromInt 2)))
 ------------ core code
 value1 :: forall a . (Eq a, Num a) => ()
 value1
diff --git a/testdata/language-features/basic-values/case05.out b/testdata/language-features/basic-values/case05.out
index 51e7f245..130dd7d3 100644
--- a/testdata/language-features/basic-values/case05.out
+++ b/testdata/language-features/basic-values/case05.out
@@ -1,8 +1,10 @@
 main is not found
 ------------ desugared source code
 value
-  = \(a :: _) -> _rhs
-    ((\(b :: _) -> case'Bool (\(_ :: _) -> _) undefined '1' (fromInt 1 == b)) a)
+  = _lhs
+    value
+    \(a :: _) -> _rhs
+      ((\(b :: _) -> case'Bool (\(_ :: _) -> _) undefined '1' (fromInt 1 == b)) a)
 ------------ core code
 value :: forall a . (Eq a, Num a) => a -> Char
 value
diff --git a/testdata/language-features/basic-values/case06.out b/testdata/language-features/basic-values/case06.out
index 0191877b..9b4ff748 100644
--- a/testdata/language-features/basic-values/case06.out
+++ b/testdata/language-features/basic-values/case06.out
@@ -1,8 +1,10 @@
 main is not found
 ------------ desugared source code
 value
-  = \(a :: _) -> _rhs
-    ((\(b :: _) -> case'Bool (\(_ :: _) -> _) '_' '1' (fromInt 1 == b)) a)
+  = _lhs
+    value
+    \(a :: _) -> _rhs
+      ((\(b :: _) -> case'Bool (\(_ :: _) -> _) '_' '1' (fromInt 1 == b)) a)
 ------------ core code
 value :: forall a . (Eq a, Num a) => a -> Char
 value
diff --git a/testdata/language-features/basic-values/def01.out b/testdata/language-features/basic-values/def01.out
index 3ada4423..6564e1b8 100644
--- a/testdata/language-features/basic-values/def01.out
+++ b/testdata/language-features/basic-values/def01.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
-unit = _rhs ()
+unit = _lhs unit (_rhs ())
 
-fun1 = \(_ :: _) -> _rhs (fromInt 1)
+fun1 = _lhs fun1 \(_ :: _) -> _rhs (fromInt 1)
 
-fun2 = \(_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) -> _rhs 'c'
+fun2 = _lhs fun2 \(_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) -> _rhs 'c'
 ------------ core code
 fun1 :: forall a b . Num b => a -> b
 fun1 = \_ a b _ -> _rhs (fromInt a b 1)
diff --git a/testdata/language-features/basic-values/def03.out b/testdata/language-features/basic-values/def03.out
index e803c077..a90c1488 100644
--- a/testdata/language-features/basic-values/def03.out
+++ b/testdata/language-features/basic-values/def03.out
@@ -1,11 +1,13 @@
 main is not found
 ------------ desugared source code
 fun
-  = \(a :: _) -> case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs '2') (fromInt 2 == a))
-    (_rhs '1')
-    (fromInt 1 == a)
+  = _lhs
+    fun
+    \(a :: _) -> case'Bool
+      (\(_ :: _) -> _)
+      (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs '2') (fromInt 2 == a))
+      (_rhs '1')
+      (fromInt 1 == a)
 ------------ core code
 fun :: forall a . (Eq a, Num a, Eq a, Num a) => a -> Char
 fun
diff --git a/testdata/language-features/basic-values/def04.out b/testdata/language-features/basic-values/def04.out
index de250fdb..127129e9 100644
--- a/testdata/language-features/basic-values/def04.out
+++ b/testdata/language-features/basic-values/def04.out
@@ -1,18 +1,22 @@
 main is not found
 ------------ desugared source code
 fun
-  = \(a :: _) -> case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '2') (fromInt 2 == a))
-    (_rhs '1')
-    (fromInt 1 == a)
+  = _lhs
+    fun
+    \(a :: _) -> case'Bool
+      (\(_ :: _) -> _)
+      (case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '2') (fromInt 2 == a))
+      (_rhs '1')
+      (fromInt 1 == a)
 
 fun2
-  = \(a :: _) (_ :: _) -> case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '2') (fromInt 2 == a))
-    (_rhs '1')
-    (fromInt 1 == a)
+  = _lhs
+    fun2
+    \(a :: _) (_ :: _) -> case'Bool
+      (\(_ :: _) -> _)
+      (case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '2') (fromInt 2 == a))
+      (_rhs '1')
+      (fromInt 1 == a)
 ------------ core code
 fun :: forall a . (Eq a, Num a, Eq a, Num a) => a -> Char
 fun
diff --git a/testdata/language-features/basic-values/deforder01.out b/testdata/language-features/basic-values/deforder01.out
index 65ee8408..932a2a54 100644
--- a/testdata/language-features/basic-values/deforder01.out
+++ b/testdata/language-features/basic-values/deforder01.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-x = _rhs '1'
+x = _lhs x (_rhs '1')
 
-y = _rhs x
+y = _lhs y (_rhs x)
 ------------ core code
 x :: Char
 x = _rhs '1'
diff --git a/testdata/language-features/basic-values/deforder02.out b/testdata/language-features/basic-values/deforder02.out
index bc81cbfd..2bfbd5b3 100644
--- a/testdata/language-features/basic-values/deforder02.out
+++ b/testdata/language-features/basic-values/deforder02.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-x = _rhs '1'
+x = _lhs x (_rhs '1')
 
-y = _rhs x
+y = _lhs y (_rhs x)
 ------------ core code
 x :: Char
 x = _rhs '1'
diff --git a/testdata/language-features/basic-values/deforder03.out b/testdata/language-features/basic-values/deforder03.out
index 6dd09a14..cf40c23e 100644
--- a/testdata/language-features/basic-values/deforder03.out
+++ b/testdata/language-features/basic-values/deforder03.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs let a = _rhs (); b = _rhs a in '1'
+value = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
 ------------ core code
 value :: Char
 value = _rhs '1'
diff --git a/testdata/language-features/basic-values/deforder04.out b/testdata/language-features/basic-values/deforder04.out
index 34f04f22..767b8a9b 100644
--- a/testdata/language-features/basic-values/deforder04.out
+++ b/testdata/language-features/basic-values/deforder04.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs let a = _rhs (); b = _rhs a in '1'
+value = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
 ------------ core code
 value :: Char
 value = _rhs '1'
diff --git a/testdata/language-features/basic-values/deforder05.out b/testdata/language-features/basic-values/deforder05.out
index c4c4eda5..7345785e 100644
--- a/testdata/language-features/basic-values/deforder05.out
+++ b/testdata/language-features/basic-values/deforder05.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs let a = _rhs (); b = _rhs a in '1'
+value = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
 ------------ core code
 value :: Char
 value = _rhs '1'
diff --git a/testdata/language-features/basic-values/deforder06.out b/testdata/language-features/basic-values/deforder06.out
index 6228b957..2a0ead81 100644
--- a/testdata/language-features/basic-values/deforder06.out
+++ b/testdata/language-features/basic-values/deforder06.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs let a = _rhs (); b = _rhs a in '1'
+value = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
 ------------ core code
 value :: Char
 value = _rhs '1'
diff --git a/testdata/language-features/basic-values/fixity01.out b/testdata/language-features/basic-values/fixity01.out
index 8f75a8f2..f4f17b40 100644
--- a/testdata/language-features/basic-values/fixity01.out
+++ b/testdata/language-features/basic-values/fixity01.out
@@ -1,12 +1,12 @@
 main is not found
 ------------ desugared source code
-funL = \(a :: _) (_ :: _) -> _rhs a
+funL = _lhs funL \(a :: _) (_ :: _) -> _rhs a
 
-funR = \(a :: _) (_ :: _) -> _rhs a
+funR = _lhs funR \(a :: _) (_ :: _) -> _rhs a
 
-(<<<<) = \(a :: _) (_ :: _) -> _rhs a
+(<<<<) = _lhs (<<<<) \(a :: _) (_ :: _) -> _rhs a
 
-(>>>>) = \(_ :: _) (a :: _) -> _rhs a
+(>>>>) = _lhs (>>>>) \(_ :: _) (a :: _) -> _rhs a
 
 infixr 7 funL
 
diff --git a/testdata/language-features/basic-values/fixity02.out b/testdata/language-features/basic-values/fixity02.out
index e018eb76..b07707af 100644
--- a/testdata/language-features/basic-values/fixity02.out
+++ b/testdata/language-features/basic-values/fixity02.out
@@ -1,12 +1,12 @@
 main is not found
 ------------ desugared source code
-funL = \(a :: _) (_ :: _) -> _rhs a
+funL = _lhs funL \(a :: _) (_ :: _) -> _rhs a
 
-funR = \(_ :: _) (a :: _) -> _rhs a
+funR = _lhs funR \(_ :: _) (a :: _) -> _rhs a
 
-(<@) = \(a :: _) (_ :: _) -> _rhs a
+(<@) = _lhs (<@) \(a :: _) (_ :: _) -> _rhs a
 
-(@>) = \(_ :: _) (a :: _) -> _rhs a
+(@>) = _lhs (@>) \(_ :: _) (a :: _) -> _rhs a
 
 infixr 7 funL
 
@@ -16,37 +16,43 @@ infixr 6 @>
 
 infixr 6 funR
 
-value1 = _rhs (() @> 'c' @> "hi" @> 1.2 :: Float)
+value1 = _lhs value1 (_rhs (() @> 'c' @> "hi" @> 1.2 :: Float))
 
-value2 = _rhs (() @> 'c' <@ "hi" @> 1.2 :: Float)
+value2 = _lhs value2 (_rhs (() @> 'c' <@ "hi" @> 1.2 :: Float))
 
-value3 = _rhs (() <@ 'c' @> "hi" @> 1.2 :: Float)
+value3 = _lhs value3 (_rhs (() <@ 'c' @> "hi" @> 1.2 :: Float))
 
-value4 = _rhs (() <@ 'c' <@ "hi" @> 1.2 :: Float)
+value4 = _lhs value4 (_rhs (() <@ 'c' <@ "hi" @> 1.2 :: Float))
 
-value5 = _rhs (() @> 'c' @> "hi" <@ 1.2 :: String)
+value5 = _lhs value5 (_rhs (() @> 'c' @> "hi" <@ 1.2 :: String))
 
-value6 = _rhs (() @> 'c' <@ "hi" <@ 1.2 :: Char)
+value6 = _lhs value6 (_rhs (() @> 'c' <@ "hi" <@ 1.2 :: Char))
 
-value7 = _rhs (() <@ 'c' @> "hi" <@ 1.2 :: String)
+value7 = _lhs value7 (_rhs (() <@ 'c' @> "hi" <@ 1.2 :: String))
 
-value8 = _rhs (() <@ 'c' <@ "hi" <@ 1.2 :: ())
+value8 = _lhs value8 (_rhs (() <@ 'c' <@ "hi" <@ 1.2 :: ()))
 
-funValue1 = _rhs (() `funR` 'c' `funR` "hi" `funR` 1.2 :: Float)
+funValue1
+  = _lhs funValue1 (_rhs (() `funR` 'c' `funR` "hi" `funR` 1.2 :: Float))
 
-funValue2 = _rhs (() `funR` 'c' `funL` "hi" `funR` 1.2 :: Float)
+funValue2
+  = _lhs funValue2 (_rhs (() `funR` 'c' `funL` "hi" `funR` 1.2 :: Float))
 
-funValue3 = _rhs (() `funL` 'c' `funR` "hi" `funR` 1.2 :: Float)
+funValue3
+  = _lhs funValue3 (_rhs (() `funL` 'c' `funR` "hi" `funR` 1.2 :: Float))
 
-funValue4 = _rhs (() `funL` 'c' `funL` "hi" `funR` 1.2 :: Float)
+funValue4
+  = _lhs funValue4 (_rhs (() `funL` 'c' `funL` "hi" `funR` 1.2 :: Float))
 
-funValue5 = _rhs (() `funR` 'c' `funR` "hi" `funL` 1.2 :: String)
+funValue5
+  = _lhs funValue5 (_rhs (() `funR` 'c' `funR` "hi" `funL` 1.2 :: String))
 
-funValue6 = _rhs (() `funR` 'c' `funL` "hi" `funL` 1.2 :: Char)
+funValue6 = _lhs funValue6 (_rhs (() `funR` 'c' `funL` "hi" `funL` 1.2 :: Char))
 
-funValue7 = _rhs (() `funL` 'c' `funR` "hi" `funL` 1.2 :: String)
+funValue7
+  = _lhs funValue7 (_rhs (() `funL` 'c' `funR` "hi" `funL` 1.2 :: String))
 
-funValue8 = _rhs (() `funL` 'c' `funL` "hi" `funL` 1.2 :: ())
+funValue8 = _lhs funValue8 (_rhs (() `funL` 'c' `funL` "hi" `funL` 1.2 :: ()))
 ------------ core code
 <@ :: forall a b . a -> b -> a
 <@ = \_ _ a _ -> _rhs a
diff --git a/testdata/language-features/basic-values/if01.out b/testdata/language-features/basic-values/if01.out
index cfac15fd..82fdb2ff 100644
--- a/testdata/language-features/basic-values/if01.out
+++ b/testdata/language-features/basic-values/if01.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs (primIfThenElse True () ())
+value1 = _lhs value1 (_rhs (primIfThenElse True () ()))
 
-value2 = _rhs (primIfThenElse False 1.0 2.0)
+value2 = _lhs value2 (_rhs (primIfThenElse False 1.0 2.0))
 ------------ core code
 value1 :: ()
 value1 = _rhs ()
diff --git a/testdata/language-features/basic-values/indentation01.out b/testdata/language-features/basic-values/indentation01.out
index 737c8ecd..f1d98545 100644
--- a/testdata/language-features/basic-values/indentation01.out
+++ b/testdata/language-features/basic-values/indentation01.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-tuple1 = _rhs ()
+tuple1 = _lhs tuple1 (_rhs ())
 
-tuple2 = _rhs ()
+tuple2 = _lhs tuple2 (_rhs ())
 ------------ core code
 tuple1 :: ()
 tuple1 = _rhs ()
diff --git a/testdata/language-features/basic-values/indentation02.out b/testdata/language-features/basic-values/indentation02.out
index 33b04d5e..0b686d97 100644
--- a/testdata/language-features/basic-values/indentation02.out
+++ b/testdata/language-features/basic-values/indentation02.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-tuple1 = _rhs ()
+tuple1 = _lhs tuple1 (_rhs ())
 
-tuple2 = _rhs ()
+tuple2 = _lhs tuple2 (_rhs ())
 ------------ core code
 tuple1 :: ()
 tuple1 = _rhs ()
diff --git a/testdata/language-features/basic-values/infix01.out b/testdata/language-features/basic-values/infix01.out
index 1ba2bd04..ced45621 100644
--- a/testdata/language-features/basic-values/infix01.out
+++ b/testdata/language-features/basic-values/infix01.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-fun = \(_ :: _) (_ :: _) -> _rhs ()
+fun = _lhs fun \(_ :: _) (_ :: _) -> _rhs ()
 
-value = \(a :: _) (b :: _) -> _rhs (a `fun` b)
+value = _lhs value \(a :: _) (b :: _) -> _rhs (a `fun` b)
 ------------ core code
 fun :: forall a b . a -> b -> ()
 fun = \_ _ _ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/infix02.out b/testdata/language-features/basic-values/infix02.out
index 8f743998..888f4d9f 100644
--- a/testdata/language-features/basic-values/infix02.out
+++ b/testdata/language-features/basic-values/infix02.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-fun = \(_ :: _) (_ :: _) (_ :: _) -> _rhs ()
+fun = _lhs fun \(_ :: _) (_ :: _) (_ :: _) -> _rhs ()
 
-value = \(a :: _) (b :: _) -> _rhs (a `fun` b)
+value = _lhs value \(a :: _) (b :: _) -> _rhs (a `fun` b)
 ------------ core code
 fun :: forall a b c . a -> b -> c -> ()
 fun = \_ _ _ _ _ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/infix03.out b/testdata/language-features/basic-values/infix03.out
index 4b6af910..9d3aa812 100644
--- a/testdata/language-features/basic-values/infix03.out
+++ b/testdata/language-features/basic-values/infix03.out
@@ -4,9 +4,9 @@ data D :: Type where
     D2 :: () -> () -> D
     D3 :: () -> () -> () -> D
 
-d2 = \(a :: _) (b :: _) -> _rhs (a `D2` b)
+d2 = _lhs d2 \(a :: _) (b :: _) -> _rhs (a `D2` b)
 
-d3 = \(a :: _) (b :: _) -> _rhs (a `D3` b)
+d3 = _lhs d3 \(a :: _) (b :: _) -> _rhs (a `D3` b)
 ------------ core code
 'D :: Type
 'D = <<type constructor with 0 indices; constructors: D2, D3>>
diff --git a/testdata/language-features/basic-values/lambda01.out b/testdata/language-features/basic-values/lambda01.out
index 591970d1..0a07171f 100644
--- a/testdata/language-features/basic-values/lambda01.out
+++ b/testdata/language-features/basic-values/lambda01.out
@@ -1,16 +1,18 @@
 main is not found
 ------------ desugared source code
-fun1 = _rhs \(_ :: _) -> ()
+fun1 = _lhs fun1 (_rhs \(_ :: _) -> ())
 
-fun2 = _rhs \(_ :: _) -> ()
+fun2 = _lhs fun2 (_rhs \(_ :: _) -> ())
 
-fun3 = _rhs \(_ :: _) -> ()
+fun3 = _lhs fun3 (_rhs \(_ :: _) -> ())
 
 fun4
-  = _rhs
-    \(_ :: _)
-        (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _)
-      -> ()
+  = _lhs
+    fun4
+    (_rhs
+      \(_ :: _)
+          (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _)
+        -> ())
 ------------ core code
 fun1 :: forall a . a -> ()
 fun1 = \_ -> _rhs \_ -> ()
diff --git a/testdata/language-features/basic-values/lambda03.out b/testdata/language-features/basic-values/lambda03.out
index 69e50ccf..f9ddcaa4 100644
--- a/testdata/language-features/basic-values/lambda03.out
+++ b/testdata/language-features/basic-values/lambda03.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-fun1 = _rhs \(_ :: _) (a :: _) (_ :: _) -> a
+fun1 = _lhs fun1 (_rhs \(_ :: _) (a :: _) (_ :: _) -> a)
 
-fun2 = \(a :: _) -> _rhs \(_ :: _) (_ :: _) (_ :: _) -> a
+fun2 = _lhs fun2 \(a :: _) -> _rhs \(_ :: _) (_ :: _) (_ :: _) -> a
 ------------ core code
 fun1 :: forall a b c . a -> b -> c -> b
 fun1 = \_ _ _ -> _rhs \_ a _ -> a
diff --git a/testdata/language-features/basic-values/let01.out b/testdata/language-features/basic-values/let01.out
index 3c1f5fa4..7d40e348 100644
--- a/testdata/language-features/basic-values/let01.out
+++ b/testdata/language-features/basic-values/let01.out
@@ -1,14 +1,21 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs let a = _rhs (fromInt 1) in fromInt 1
+value1 = _lhs value1 (_rhs let a = _lhs x (_rhs (fromInt 1)) in fromInt 1)
 
-value2 = _rhs let a = _rhs (fromInt 1) in fromInt 1
+value2 = _lhs value2 (_rhs let a = _lhs x (_rhs (fromInt 1)) in fromInt 1)
 
-value3 = _rhs let a = _rhs (fromInt 1); b = _rhs 'c' in fromInt 1
+value3
+  = _lhs
+    value3
+    (_rhs let a = _lhs x (_rhs (fromInt 1)); b = _lhs y (_rhs 'c') in fromInt 1)
 
-value4 = _rhs let a = _rhs (fromInt 1) in fromInt 1
+value4 = _lhs value4 (_rhs let a = _lhs x (_rhs (fromInt 1)) in fromInt 1)
 
-value5 = _rhs let a = _rhs (fromInt 1); b = _rhs (fromInt 2) in fromInt 1
+value5
+  = _lhs
+    value5
+    (_rhs
+      let a = _lhs x (_rhs (fromInt 1)); b = _lhs y (_rhs (fromInt 2)) in fromInt 1)
 ------------ core code
 value1 :: forall a . Num a => a
 value1 = \a b -> _rhs (fromInt a b 1)
diff --git a/testdata/language-features/basic-values/let02.out b/testdata/language-features/basic-values/let02.out
index 4ca11163..f9de03b4 100644
--- a/testdata/language-features/basic-values/let02.out
+++ b/testdata/language-features/basic-values/let02.out
@@ -1,12 +1,20 @@
 main is not found
 ------------ desugared source code
 value
-  = _rhs
-    let
-      a = _rhs ();
-      b = _rhs let d = _rhs 'A' in ();
-      c = _rhs let e = _rhs (); f = _rhs (fromInt 1); g = _rhs "hello" in 'B'
-      in ()
+  = _lhs
+    value
+    (_rhs
+      let
+        a = _lhs x (_rhs ());
+        b = _lhs y (_rhs let d = _lhs c (_rhs 'A') in ());
+        c
+          = _lhs
+            z
+            (_rhs
+              let
+                e = _lhs a (_rhs ()); f = _lhs b (_rhs (fromInt 1)); g = _lhs c (_rhs "hello")
+                in 'B')
+        in ())
 ------------ core code
 value :: ()
 value = _rhs ()
diff --git a/testdata/language-features/basic-values/literal01.out b/testdata/language-features/basic-values/literal01.out
index 4619304a..4eca17da 100644
--- a/testdata/language-features/basic-values/literal01.out
+++ b/testdata/language-features/basic-values/literal01.out
@@ -1,20 +1,20 @@
 main is not found
 ------------ desugared source code
-intValue1 = _rhs (fromInt 0)
+intValue1 = _lhs intValue1 (_rhs (fromInt 0))
 
-intValue2 = _rhs (fromInt 1)
+intValue2 = _lhs intValue2 (_rhs (fromInt 1))
 
-intValue3 = _rhs (fromInt 12345)
+intValue3 = _lhs intValue3 (_rhs (fromInt 12345))
 
-floatValue1 = _rhs 2.0
+floatValue1 = _lhs floatValue1 (_rhs 2.0)
 
-floatValue2 = _rhs 123400.0
+floatValue2 = _lhs floatValue2 (_rhs 123400.0)
 
-charValue = _rhs 'A'
+charValue = _lhs charValue (_rhs 'A')
 
-stringValue1 = _rhs "Hello World"
+stringValue1 = _lhs stringValue1 (_rhs "Hello World")
 
-stringValue2 = _rhs "\nHello World\tagain!\r\n"
+stringValue2 = _lhs stringValue2 (_rhs "\nHello World\tagain!\r\n")
 ------------ core code
 charValue :: Char
 charValue = _rhs 'A'
diff --git a/testdata/language-features/basic-values/operator01.out b/testdata/language-features/basic-values/operator01.out
index f239d6b3..3b6dd323 100644
--- a/testdata/language-features/basic-values/operator01.out
+++ b/testdata/language-features/basic-values/operator01.out
@@ -1,12 +1,12 @@
 main is not found
 ------------ desugared source code
-(#$#) = \(_ :: _) (_ :: _) -> _rhs ()
+(#$#) = _lhs (#$#) \(_ :: _) (_ :: _) -> _rhs ()
 
-($$#) = \(_ :: _) (_ :: _) -> _rhs ()
+($$#) = _lhs ($$#) \(_ :: _) (_ :: _) -> _rhs ()
 
-($$$#) = \(_ :: _) (_ :: _) -> _rhs ()
+($$$#) = _lhs ($$$#) \(_ :: _) (_ :: _) -> _rhs ()
 
-($$$) = \(_ :: _) (_ :: _) -> _rhs ()
+($$$) = _lhs ($$$) \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 #$# :: forall a b . a -> b -> ()
 #$# = \_ _ _ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/operator05.out b/testdata/language-features/basic-values/operator05.out
index 6a12b629..c8f2cbc8 100644
--- a/testdata/language-features/basic-values/operator05.out
+++ b/testdata/language-features/basic-values/operator05.out
@@ -1,6 +1,7 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs let a = \(_ :: _) (_ :: _) -> _rhs () in a () ()
+value1
+  = _lhs value1 (_rhs let a = _lhs (+=+) \(_ :: _) (_ :: _) -> _rhs () in a () ())
 ------------ core code
 value1 :: ()
 value1 = _rhs ()
diff --git a/testdata/language-features/basic-values/operator06.out b/testdata/language-features/basic-values/operator06.out
index 31724acd..84f75660 100644
--- a/testdata/language-features/basic-values/operator06.out
+++ b/testdata/language-features/basic-values/operator06.out
@@ -1,6 +1,7 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs let a = \(_ :: _) (_ :: _) -> _rhs () in a () ()
+value1
+  = _lhs value1 (_rhs let a = _lhs (+=+) \(_ :: _) (_ :: _) -> _rhs () in a () ())
 ------------ core code
 value1 :: ()
 value1 = _rhs ()
diff --git a/testdata/language-features/basic-values/shadowing01.out b/testdata/language-features/basic-values/shadowing01.out
index 5233865a..b1288270 100644
--- a/testdata/language-features/basic-values/shadowing01.out
+++ b/testdata/language-features/basic-values/shadowing01.out
@@ -1,18 +1,28 @@
 main is not found
 ------------ desugared source code
 value
-  = _rhs
-    let
-      a = _rhs 'A';
-      b = _rhs "hello";
-      c
-        = _rhs
-          let
-            d = _rhs (fromInt 1);
-            e = _rhs 2.12;
-            f = _rhs let g = _rhs (); h = _rhs 'C'; i = _rhs 3.12 in "world"
-            in ()
-      in '7'
+  = _lhs
+    value
+    (_rhs
+      let
+        a = _lhs x (_rhs 'A');
+        b = _lhs y (_rhs "hello");
+        c
+          = _lhs
+            c
+            (_rhs
+              let
+                d = _lhs x (_rhs (fromInt 1));
+                e = _lhs y (_rhs 2.12);
+                f
+                  = _lhs
+                    c
+                    (_rhs
+                      let
+                        g = _lhs x (_rhs ()); h = _lhs y (_rhs 'C'); i = _lhs c (_rhs 3.12)
+                        in "world")
+                in ())
+        in '7')
 ------------ core code
 value :: Char
 value = _rhs '7'
diff --git a/testdata/language-features/basic-values/shadowing02.out b/testdata/language-features/basic-values/shadowing02.out
index 19a72446..7edd4cef 100644
--- a/testdata/language-features/basic-values/shadowing02.out
+++ b/testdata/language-features/basic-values/shadowing02.out
@@ -1,23 +1,36 @@
 main is not found
 ------------ desugared source code
-c = _rhs (fromInt 7)
+c = _lhs c (_rhs (fromInt 7))
 
-world = _rhs "world"
+world = _lhs world (_rhs "world")
 
 value2
-  = _rhs
-    let
-      a = _rhs 'A';
-      b = _rhs "hello";
-      c = _rhs (fromInt 123);
-      d
-        = _rhs
-          let
-            e = _rhs (fromInt 1);
-            f = _rhs 2.12;
-            g = _rhs let h = _rhs (); i = _rhs 'C'; j = _rhs 3.12; k = _rhs c in world
-            in ()
-      in '7'
+  = _lhs
+    value2
+    (_rhs
+      let
+        a = _lhs x (_rhs 'A');
+        b = _lhs y (_rhs "hello");
+        c = _lhs w (_rhs (fromInt 123));
+        d
+          = _lhs
+            c
+            (_rhs
+              let
+                e = _lhs x (_rhs (fromInt 1));
+                f = _lhs y (_rhs 2.12);
+                g
+                  = _lhs
+                    c
+                    (_rhs
+                      let
+                        h = _lhs x (_rhs ());
+                        i = _lhs y (_rhs 'C');
+                        j = _lhs c (_rhs 3.12);
+                        k = _lhs d (_rhs c)
+                        in world)
+                in ())
+        in '7')
 ------------ core code
 c :: forall a . Num a => a
 c = \a b -> _rhs (fromInt a b 7)
diff --git a/testdata/language-features/basic-values/shadowing03.out b/testdata/language-features/basic-values/shadowing03.out
index 0ee5fa0e..f796c908 100644
--- a/testdata/language-features/basic-values/shadowing03.out
+++ b/testdata/language-features/basic-values/shadowing03.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-x = \(_ :: _) (_ :: _) -> _rhs ()
+x = _lhs x \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 x :: forall a b . a -> b -> ()
 x = \_ _ _ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/shadowing04.out b/testdata/language-features/basic-values/shadowing04.out
index c55d2dfe..59d10c41 100644
--- a/testdata/language-features/basic-values/shadowing04.out
+++ b/testdata/language-features/basic-values/shadowing04.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-__ = \(_ :: _) (_ :: _) -> _rhs ()
+__ = _lhs __ \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 __ :: forall a b . a -> b -> ()
 __ = \_ _ _ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/tuple01.out b/testdata/language-features/basic-values/tuple01.out
index fbe79611..b3a8a352 100644
--- a/testdata/language-features/basic-values/tuple01.out
+++ b/testdata/language-features/basic-values/tuple01.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-unit = _rhs ()
+unit = _lhs unit (_rhs ())
 ------------ core code
 unit :: ()
 unit = _rhs ()
diff --git a/testdata/language-features/basic-values/tuple02.out b/testdata/language-features/basic-values/tuple02.out
index 3b6e4410..d221d37a 100644
--- a/testdata/language-features/basic-values/tuple02.out
+++ b/testdata/language-features/basic-values/tuple02.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
-tuple1 = _rhs (fromInt 1, 2.3, 'D', "string", ())
+tuple1 = _lhs tuple1 (_rhs (fromInt 1, 2.3, 'D', "string", ()))
 
-tuple2 = _rhs ((), ())
+tuple2 = _lhs tuple2 (_rhs ((), ()))
 
-tuple3 = _rhs (("name", 'c'), ())
+tuple3 = _lhs tuple3 (_rhs (("name", 'c'), ()))
 ------------ core code
 tuple1 :: forall a . Num a => (a, Float, Char, String, ())
 tuple1 = \a b -> _rhs (fromInt a b 1, 2.3, 'D', "string", ())
diff --git a/testdata/language-features/basic-values/typesig01.out b/testdata/language-features/basic-values/typesig01.out
index c36d5cf2..964ba8a7 100644
--- a/testdata/language-features/basic-values/typesig01.out
+++ b/testdata/language-features/basic-values/typesig01.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
 value1 :: Char
-value1 = _rhs 'a'
+value1 = _lhs value1 (_rhs 'a')
 
 value2 :: Char
-value2 = _rhs 'a'
+value2 = _lhs value2 (_rhs 'a')
 ------------ core code
 value1 :: Char
 value1 = _rhs 'a'
diff --git a/testdata/language-features/basic-values/typesig02.out b/testdata/language-features/basic-values/typesig02.out
index 415f46d9..b9c50d6b 100644
--- a/testdata/language-features/basic-values/typesig02.out
+++ b/testdata/language-features/basic-values/typesig02.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs ('a' :: Char)
+value1 = _lhs value1 (_rhs ('a' :: Char))
 
-value2 = _rhs ('a' :: Char)
+value2 = _lhs value2 (_rhs ('a' :: Char))
 ------------ core code
 value1 :: Char
 value1 = _rhs 'a'
diff --git a/testdata/language-features/basic-values/typesig03.out b/testdata/language-features/basic-values/typesig03.out
index 738ddca8..a26d2bef 100644
--- a/testdata/language-features/basic-values/typesig03.out
+++ b/testdata/language-features/basic-values/typesig03.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
 fun1 :: forall (a :: _) (b :: _) (c :: _) . a -> b -> c -> ()
-fun1 = \(_ :: _) (_ :: _) (_ :: _) -> _rhs ()
+fun1 = _lhs fun1 \(_ :: _) (_ :: _) (_ :: _) -> _rhs ()
 
 fun2 :: forall (a :: _) (b :: _) (c :: _) . a -> b -> c -> ()
-fun2 = \(_ :: _) (_ :: _) (_ :: _) -> _rhs ()
+fun2 = _lhs fun2 \(_ :: _) (_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 fun1 :: forall a b c . a -> b -> c -> ()
 fun1 = \_ _ _ _ _ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/typesig04.out b/testdata/language-features/basic-values/typesig04.out
index 0df6fc91..4e55cfac 100644
--- a/testdata/language-features/basic-values/typesig04.out
+++ b/testdata/language-features/basic-values/typesig04.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
 fun1 :: forall (a :: _) (b :: _) (c :: _) . a -> (b -> c) -> ()
-fun1 = \(_ :: _) (_ :: _) -> _rhs ()
+fun1 = _lhs fun1 \(_ :: _) (_ :: _) -> _rhs ()
 
 fun2 :: forall (a :: _) (b :: _) (c :: _) . a -> (b -> c) -> ()
-fun2 = \(_ :: _) (_ :: _) -> _rhs ()
+fun2 = _lhs fun2 \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 fun1 :: forall a b c . a -> (b -> c) -> ()
 fun1 = \_ _ _ _ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/typesig05.out b/testdata/language-features/basic-values/typesig05.out
index b5fdd7ec..7ca5e11a 100644
--- a/testdata/language-features/basic-values/typesig05.out
+++ b/testdata/language-features/basic-values/typesig05.out
@@ -1,18 +1,18 @@
 main is not found
 ------------ desugared source code
-funL = \(a :: _) (_ :: _) -> _rhs a
+funL = _lhs funL \(a :: _) (_ :: _) -> _rhs a
 
-funR = \(_ :: _) (a :: _) -> _rhs a
+funR = _lhs funR \(_ :: _) (a :: _) -> _rhs a
 
-value1 = _rhs (funL 'a' "b" :: Char)
+value1 = _lhs value1 (_rhs (funL 'a' "b" :: Char))
 
-value2 = _rhs (funR 'a' "b" :: String)
+value2 = _lhs value2 (_rhs (funR 'a' "b" :: String))
 
 value3 :: Char
-value3 = _rhs (funL 'a' "b")
+value3 = _lhs value3 (_rhs (funL 'a' "b"))
 
 value4 :: String
-value4 = _rhs (funR 'a' "b")
+value4 = _lhs value4 (_rhs (funR 'a' "b"))
 ------------ core code
 funL :: forall a b . a -> b -> a
 funL = \_ _ a _ -> _rhs a
diff --git a/testdata/language-features/basic-values/typesig06.out b/testdata/language-features/basic-values/typesig06.out
index 5b74205a..6cc32fea 100644
--- a/testdata/language-features/basic-values/typesig06.out
+++ b/testdata/language-features/basic-values/typesig06.out
@@ -1,12 +1,12 @@
 main is not found
 ------------ desugared source code
-funL = \(a :: _) (_ :: _) -> _rhs a
+funL = _lhs funL \(a :: _) (_ :: _) -> _rhs a
 
-(<@) = \(a :: _) (_ :: _) -> _rhs a
+(<@) = _lhs (<@) \(a :: _) (_ :: _) -> _rhs a
 
-value1 = _rhs ("hi" <@ 1.2 :: String)
+value1 = _lhs value1 (_rhs ("hi" <@ 1.2 :: String))
 
-value2 = _rhs ("hi" `funL` 1.2 :: String)
+value2 = _lhs value2 (_rhs ("hi" `funL` 1.2 :: String))
 ------------ core code
 <@ :: forall a b . a -> b -> a
 <@ = \_ _ a _ -> _rhs a
diff --git a/testdata/language-features/basic-values/typesig07.out b/testdata/language-features/basic-values/typesig07.out
index a374ab2a..c8f1b04a 100644
--- a/testdata/language-features/basic-values/typesig07.out
+++ b/testdata/language-features/basic-values/typesig07.out
@@ -1,22 +1,22 @@
 main is not found
 ------------ desugared source code
 value1 :: Int
-value1 = _rhs (fromInt 1)
+value1 = _lhs value1 (_rhs (fromInt 1))
 
 value2 :: Int
-value2 = _rhs (fromInt 2)
+value2 = _lhs value2 (_rhs (fromInt 2))
 
 value3 :: Int
-value3 = _rhs (fromInt 3)
+value3 = _lhs value3 (_rhs (fromInt 3))
 
 value4 :: () -> () -> ()
-value4 = \(_ :: _) (_ :: _) -> _rhs ()
+value4 = _lhs value4 \(_ :: _) (_ :: _) -> _rhs ()
 
 (@@@) :: () -> () -> ()
-(@@@) = \(_ :: _) (_ :: _) -> _rhs ()
+(@@@) = _lhs (@@@) \(_ :: _) (_ :: _) -> _rhs ()
 
 value6 :: () -> () -> ()
-value6 = \(_ :: _) (_ :: _) -> _rhs ()
+value6 = _lhs value6 \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 @@@ :: () -> () -> ()
 @@@ = \_ _ -> _rhs ()
diff --git a/testdata/language-features/basic-values/typesyn01.out b/testdata/language-features/basic-values/typesyn01.out
index 442aeac3..04b3421a 100644
--- a/testdata/language-features/basic-values/typesyn01.out
+++ b/testdata/language-features/basic-values/typesyn01.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-'MyUnit = _rhs ' ()
+'MyUnit = _lhs 'MyUnit (_rhs ' ())
 ------------ core code
 'MyUnit :: Type
 'MyUnit = _rhs ' ()
diff --git a/testdata/language-features/basic-values/typesyn02.out b/testdata/language-features/basic-values/typesyn02.out
index fa019006..efca73f5 100644
--- a/testdata/language-features/basic-values/typesyn02.out
+++ b/testdata/language-features/basic-values/typesyn02.out
@@ -1,9 +1,9 @@
 main is not found
 ------------ desugared source code
-'MyUnit = _rhs ' ()
+'MyUnit = _lhs 'MyUnit (_rhs ' ())
 
 fun :: forall (a :: _) . a -> MyUnit -> MyUnit
-fun = \(_ :: _) (a :: _) -> hlistNilCase _ (_rhs ()) a
+fun = _lhs fun \(_ :: _) (a :: _) -> hlistNilCase _ (_rhs ()) a
 ------------ core code
 'MyUnit :: Type
 'MyUnit = _rhs ' ()
diff --git a/testdata/language-features/basic-values/where01.out b/testdata/language-features/basic-values/where01.out
index 843b762e..3b56a3c4 100644
--- a/testdata/language-features/basic-values/where01.out
+++ b/testdata/language-features/basic-values/where01.out
@@ -1,26 +1,28 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs let a = _rhs () in ()
+value1 = _lhs value1 (_rhs let a = _lhs x (_rhs ()) in ())
 
-value2 = _rhs let a = _rhs () in a
+value2 = _lhs value2 (_rhs let a = _lhs x (_rhs ()) in a)
 
-value3 = _rhs let a = _rhs (); b = _rhs () in a
+value3 = _lhs value3 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
 
-value4 = _rhs let a = _rhs (); b = _rhs () in b
+value4 = _lhs value4 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in b)
 
-value5 = _rhs let a = _rhs (); b = _rhs () in a
+value5 = _lhs value5 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
 
-value6 = _rhs ()
+value6 = _lhs value6 (_rhs ())
 
-value7 = _rhs ()
+value7 = _lhs value7 (_rhs ())
 
-value8 = _rhs ()
+value8 = _lhs value8 (_rhs ())
 
-value9 = _rhs let a = _rhs (); b = _rhs () in a
+value9 = _lhs value9 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
 
-value10 = _rhs let a = _rhs (); b = _rhs () in a
+value10
+  = _lhs value10 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
 
-value11 = _rhs let a = _rhs (); b = _rhs () in a
+value11
+  = _lhs value11 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
 ------------ core code
 value1 :: ()
 value1 = _rhs ()
diff --git a/testdata/language-features/basic-values/where04.out b/testdata/language-features/basic-values/where04.out
index 9eb5f765..3095e9d3 100644
--- a/testdata/language-features/basic-values/where04.out
+++ b/testdata/language-features/basic-values/where04.out
@@ -1,10 +1,13 @@
 main is not found
 ------------ desugared source code
-value1 = _rhs let a = _rhs let b = _rhs () in b in a
+value1
+  = _lhs value1 (_rhs let a = _lhs x (_rhs let b = _lhs y (_rhs ()) in b) in a)
 
-value2 = _rhs let a = _rhs let b = _rhs () in b in a
+value2
+  = _lhs value2 (_rhs let a = _lhs x (_rhs let b = _lhs y (_rhs ()) in b) in a)
 
-value3 = _rhs let a = _rhs let b = _rhs () in b in a
+value3
+  = _lhs value3 (_rhs let a = _lhs x (_rhs let b = _lhs y (_rhs ()) in b) in a)
 ------------ core code
 value1 :: ()
 value1 = _rhs ()
diff --git a/testdata/language-features/basic-values/where05.out b/testdata/language-features/basic-values/where05.out
index 55c7a06d..0dc19f61 100644
--- a/testdata/language-features/basic-values/where05.out
+++ b/testdata/language-features/basic-values/where05.out
@@ -1,40 +1,48 @@
 main is not found
 ------------ desugared source code
 value1
-  = _rhs
-    ((\(a :: _) -> case'Bool
-        (\(_ :: _) -> _)
-        ()
-        (let b = _rhs () in b)
-        (fromInt 1 == a))
-      (fromInt 1))
+  = _lhs
+    value1
+    (_rhs
+      ((\(a :: _) -> case'Bool
+          (\(_ :: _) -> _)
+          ()
+          (let b = _lhs x (_rhs ()) in b)
+          (fromInt 1 == a))
+        (fromInt 1)))
 
 value2
-  = _rhs
-    ((\(a :: _) -> case'Bool
-        (\(_ :: _) -> _)
-        ()
-        (let b = _rhs () in b)
-        (fromInt 1 == a))
-      (fromInt 1))
+  = _lhs
+    value2
+    (_rhs
+      ((\(a :: _) -> case'Bool
+          (\(_ :: _) -> _)
+          ()
+          (let b = _lhs x (_rhs ()) in b)
+          (fromInt 1 == a))
+        (fromInt 1)))
 
 value3
-  = _rhs
-    ((\(a :: _) -> case'Bool
-        (\(_ :: _) -> _)
-        ()
-        (let b = _rhs () in b)
-        (fromInt 1 == a))
-      (fromInt 1))
+  = _lhs
+    value3
+    (_rhs
+      ((\(a :: _) -> case'Bool
+          (\(_ :: _) -> _)
+          ()
+          (let b = _lhs x (_rhs ()) in b)
+          (fromInt 1 == a))
+        (fromInt 1)))
 
 value4
-  = _rhs
-    let a = _rhs () in (\(b :: _) -> case'Bool
-        (\(_ :: _) -> _)
-        ()
-        a
-        (fromInt 1 == b))
-      (fromInt 1)
+  = _lhs
+    value4
+    (_rhs
+      let a = _lhs x (_rhs ()) in (\(b :: _) -> case'Bool
+          (\(_ :: _) -> _)
+          ()
+          a
+          (fromInt 1 == b))
+        (fromInt 1))
 ------------ core code
 value1 :: forall a . (Eq a, Num a) => ()
 value1
diff --git a/testdata/language-features/basic-values/wildcard01.out b/testdata/language-features/basic-values/wildcard01.out
index 9fa1c034..b462aac7 100644
--- a/testdata/language-features/basic-values/wildcard01.out
+++ b/testdata/language-features/basic-values/wildcard01.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-funUnit = \(_ :: _) -> _rhs ()
+funUnit = _lhs funUnit \(_ :: _) -> _rhs ()
 ------------ core code
 funUnit :: forall a . a -> ()
 funUnit = \_ _ -> _rhs ()
diff --git a/testdata/language-features/guard/guard01.out b/testdata/language-features/guard/guard01.out
index 3e232549..e32f6dfc 100644
--- a/testdata/language-features/guard/guard01.out
+++ b/testdata/language-features/guard/guard01.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs ()) True
+value = _lhs value (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs ()) True)
 ------------ core code
 value :: ()
 value = _rhs ()
diff --git a/testdata/language-features/guard/guard03.out b/testdata/language-features/guard/guard03.out
index 3e44257a..794931e9 100644
--- a/testdata/language-features/guard/guard03.out
+++ b/testdata/language-features/guard/guard03.out
@@ -1,11 +1,13 @@
 main is not found
 ------------ desugared source code
 value
-  = case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
-    (_rhs "True")
-    True
+  = _lhs
+    value
+    (case'Bool
+      (\(_ :: _) -> _)
+      (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
+      (_rhs "True")
+      True)
 ------------ core code
 value :: String
 value = _rhs "True"
diff --git a/testdata/language-features/guard/guard04.out b/testdata/language-features/guard/guard04.out
index 3becb569..6c87ff14 100644
--- a/testdata/language-features/guard/guard04.out
+++ b/testdata/language-features/guard/guard04.out
@@ -1,6 +1,7 @@
 main is not found
 ------------ desugared source code
-value = case'Bool (\(_ :: _) -> _) (_rhs "False") (_rhs "True") True
+value
+  = _lhs value (case'Bool (\(_ :: _) -> _) (_rhs "False") (_rhs "True") True)
 ------------ core code
 value :: String
 value = _rhs "True"
diff --git a/testdata/language-features/guard/guard06.out b/testdata/language-features/guard/guard06.out
index aa385877..778d4a8d 100644
--- a/testdata/language-features/guard/guard06.out
+++ b/testdata/language-features/guard/guard06.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-value = _rhs ()
+value = _lhs value (_rhs ())
 ------------ core code
 value :: ()
 value = _rhs ()
diff --git a/testdata/language-features/guard/guard07.out b/testdata/language-features/guard/guard07.out
index 81726eed..06c8a716 100644
--- a/testdata/language-features/guard/guard07.out
+++ b/testdata/language-features/guard/guard07.out
@@ -1,11 +1,13 @@
 main is not found
 ------------ desugared source code
 value
-  = case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
-    (_rhs "True")
-    True
+  = _lhs
+    value
+    (case'Bool
+      (\(_ :: _) -> _)
+      (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
+      (_rhs "True")
+      True)
 ------------ core code
 value :: String
 value = _rhs "True"
diff --git a/testdata/language-features/guard/guard08.out b/testdata/language-features/guard/guard08.out
index 5d6e6bdc..069c68c4 100644
--- a/testdata/language-features/guard/guard08.out
+++ b/testdata/language-features/guard/guard08.out
@@ -1,11 +1,13 @@
 main is not found
 ------------ desugared source code
 value
-  = case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
-    (_rhs "True")
-    True
+  = _lhs
+    value
+    (case'Bool
+      (\(_ :: _) -> _)
+      (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
+      (_rhs "True")
+      True)
 ------------ core code
 value :: String
 value = _rhs "True"
diff --git a/testdata/language-features/guard/guard09.out b/testdata/language-features/guard/guard09.out
index 4b580469..b7c3f36e 100644
--- a/testdata/language-features/guard/guard09.out
+++ b/testdata/language-features/guard/guard09.out
@@ -1,11 +1,13 @@
 main is not found
 ------------ desugared source code
 value
-  = case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
-    (_rhs "True")
-    True
+  = _lhs
+    value
+    (case'Bool
+      (\(_ :: _) -> _)
+      (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs "False") False)
+      (_rhs "True")
+      True)
 ------------ core code
 value :: String
 value = _rhs "True"
diff --git a/testdata/language-features/guard/guard11.out b/testdata/language-features/guard/guard11.out
index a08332c1..ea80eef0 100644
--- a/testdata/language-features/guard/guard11.out
+++ b/testdata/language-features/guard/guard11.out
@@ -1,6 +1,9 @@
 main is not found
 ------------ desugared source code
-fun = \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs "False") (_rhs "True") a
+fun
+  = _lhs
+    fun
+    \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs "False") (_rhs "True") a
 ------------ core code
 fun :: Bool -> String
 fun = \a -> case'Bool (\_ -> 'String) (_rhs "False") (_rhs "True") a
diff --git a/testdata/language-features/guard/guard13.out b/testdata/language-features/guard/guard13.out
index 5498c290..6f9005bc 100644
--- a/testdata/language-features/guard/guard13.out
+++ b/testdata/language-features/guard/guard13.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-fun = \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs ()) (_rhs ()) a
+fun = _lhs fun \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs ()) (_rhs ()) a
 ------------ core code
 fun :: Bool -> ()
 fun = \a -> case'Bool (\_ -> ' ()) (_rhs ()) (_rhs ()) a
diff --git a/testdata/language-features/guard/guard14.out b/testdata/language-features/guard/guard14.out
index 6e6f225c..1a0acd2a 100644
--- a/testdata/language-features/guard/guard14.out
+++ b/testdata/language-features/guard/guard14.out
@@ -1,6 +1,10 @@
 main is not found
 ------------ desugared source code
-value = _rhs let a = case'Bool (\(_ :: _) -> _) (_rhs ()) (_rhs ()) True in ()
+value
+  = _lhs
+    value
+    (_rhs
+      let a = _lhs x (case'Bool (\(_ :: _) -> _) (_rhs ()) (_rhs ()) True) in ())
 ------------ core code
 value :: ()
 value = _rhs ()
diff --git a/testdata/language-features/guard/guard15.out b/testdata/language-features/guard/guard15.out
index 3d01ff73..9314863f 100644
--- a/testdata/language-features/guard/guard15.out
+++ b/testdata/language-features/guard/guard15.out
@@ -1,6 +1,10 @@
 main is not found
 ------------ desugared source code
-value = _rhs let a = case'Bool (\(_ :: _) -> _) (_rhs ()) (_rhs ()) True in ()
+value
+  = _lhs
+    value
+    (_rhs
+      let a = _lhs x (case'Bool (\(_ :: _) -> _) (_rhs ()) (_rhs ()) True) in ())
 ------------ core code
 value :: ()
 value = _rhs ()
diff --git a/testdata/language-features/guard/guard16.out b/testdata/language-features/guard/guard16.out
index 1a574cf7..a9867165 100644
--- a/testdata/language-features/guard/guard16.out
+++ b/testdata/language-features/guard/guard16.out
@@ -1,13 +1,15 @@
 main is not found
 ------------ desugared source code
 value
-  = _rhs
-    ((\(a :: _) -> case'Bool
-        (\(_ :: _) -> _)
-        ()
-        (case'Bool (\(_ :: _) -> _) () () True)
-        (fromInt 1 == a))
-      (fromInt 1))
+  = _lhs
+    value
+    (_rhs
+      ((\(a :: _) -> case'Bool
+          (\(_ :: _) -> _)
+          ()
+          (case'Bool (\(_ :: _) -> _) () () True)
+          (fromInt 1 == a))
+        (fromInt 1)))
 ------------ core code
 value :: forall a . (Eq a, Num a) => ()
 value
diff --git a/testdata/language-features/module/Hello01.out b/testdata/language-features/module/Hello01.out
index 0c553aa4..30490325 100644
--- a/testdata/language-features/module/Hello01.out
+++ b/testdata/language-features/module/Hello01.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 
-world = _rhs "world"
+world = _lhs world (_rhs "world")
 ------------ core code
 hello :: String
 hello = _rhs "hello"
diff --git a/testdata/language-features/module/Hello02.out b/testdata/language-features/module/Hello02.out
index 86d52127..4a12836e 100644
--- a/testdata/language-features/module/Hello02.out
+++ b/testdata/language-features/module/Hello02.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 
-world = _rhs "world"
+world = _lhs world (_rhs "world")
 ------------ core code
 hello :: String
 hello = _rhs "hello"
diff --git a/testdata/language-features/module/Hello03.out b/testdata/language-features/module/Hello03.out
index 66b7e036..87981272 100644
--- a/testdata/language-features/module/Hello03.out
+++ b/testdata/language-features/module/Hello03.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-greeting = _rhs 'G'
+greeting = _lhs greeting (_rhs 'G')
 
-value = _rhs 12.2
+value = _lhs value (_rhs 12.2)
 ------------ core code
 greeting :: Char
 greeting = _rhs 'G'
diff --git a/testdata/language-features/module/ModulePackage/SubModule01.out b/testdata/language-features/module/ModulePackage/SubModule01.out
index 71c67233..f4408bde 100644
--- a/testdata/language-features/module/ModulePackage/SubModule01.out
+++ b/testdata/language-features/module/ModulePackage/SubModule01.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "Hello"
+hello = _lhs hello (_rhs "Hello")
 ------------ core code
 hello :: String
 hello = _rhs "Hello"
diff --git a/testdata/language-features/module/Moduledef06.out b/testdata/language-features/module/Moduledef06.out
index 5036cb7f..01116115 100644
--- a/testdata/language-features/module/Moduledef06.out
+++ b/testdata/language-features/module/Moduledef06.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 ------------ core code
 hello :: String
 hello = _rhs "hello"
diff --git a/testdata/language-features/module/Moduledef07.out b/testdata/language-features/module/Moduledef07.out
index b75130a3..85bccf88 100644
--- a/testdata/language-features/module/Moduledef07.out
+++ b/testdata/language-features/module/Moduledef07.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 ------------ core code
 hello :: String
 hello = _rhs "hello"
diff --git a/testdata/language-features/module/Moduledef08.out b/testdata/language-features/module/Moduledef08.out
index 4b1c55aa..2c303d27 100644
--- a/testdata/language-features/module/Moduledef08.out
+++ b/testdata/language-features/module/Moduledef08.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 ------------ core code
 ------------ tooltips
 testdata/language-features/module/Moduledef08.lc 5:1-5:6
diff --git a/testdata/language-features/module/Moduledef09.out b/testdata/language-features/module/Moduledef09.out
index 0aea411c..077f20e4 100644
--- a/testdata/language-features/module/Moduledef09.out
+++ b/testdata/language-features/module/Moduledef09.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 
-world = _rhs "world"
+world = _lhs world (_rhs "world")
 ------------ core code
 hello :: String
 hello = _rhs "hello"
diff --git a/testdata/language-features/module/Moduledef10.out b/testdata/language-features/module/Moduledef10.out
index ec9a574e..b05b9d4c 100644
--- a/testdata/language-features/module/Moduledef10.out
+++ b/testdata/language-features/module/Moduledef10.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 
-world = _rhs "world"
+world = _lhs world (_rhs "world")
 
-value = _rhs ()
+value = _lhs value (_rhs ())
 ------------ core code
 hello :: String
 hello = _rhs "hello"
diff --git a/testdata/language-features/module/Moduledef13.out b/testdata/language-features/module/Moduledef13.out
index f1cf03de..167125c8 100644
--- a/testdata/language-features/module/Moduledef13.out
+++ b/testdata/language-features/module/Moduledef13.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-hello = _rhs "hello"
+hello = _lhs hello (_rhs "hello")
 ------------ core code
 hello :: String
 hello = _rhs "hello"
diff --git a/testdata/language-features/module/TypeSyn01Mod.out b/testdata/language-features/module/TypeSyn01Mod.out
index 109f5ee9..54a83cfe 100644
--- a/testdata/language-features/module/TypeSyn01Mod.out
+++ b/testdata/language-features/module/TypeSyn01Mod.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-'MyUnit = _rhs ' ()
+'MyUnit = _lhs 'MyUnit (_rhs ' ())
 ------------ core code
 'MyUnit :: Type
 'MyUnit = _rhs ' ()
diff --git a/testdata/language-features/module/import01.out b/testdata/language-features/module/import01.out
index 6ccf9702..8705a150 100644
--- a/testdata/language-features/module/import01.out
+++ b/testdata/language-features/module/import01.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-x = _rhs hello
+x = _lhs x (_rhs hello)
 ------------ core code
 x :: String
 x = _rhs "hello"
diff --git a/testdata/language-features/module/import05.out b/testdata/language-features/module/import05.out
index 3d820de9..90eff292 100644
--- a/testdata/language-features/module/import05.out
+++ b/testdata/language-features/module/import05.out
@@ -1,7 +1,7 @@
 main is not found
 ------------ desugared source code
 x :: String
-x = _rhs hello
+x = _lhs x (_rhs hello)
 ------------ core code
 x :: String
 x = _rhs "hello"
diff --git a/testdata/language-features/module/import06.out b/testdata/language-features/module/import06.out
index ae0e10e5..af5885e2 100644
--- a/testdata/language-features/module/import06.out
+++ b/testdata/language-features/module/import06.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-hello = _rhs ()
+hello = _lhs hello (_rhs ())
 
-x = _rhs world
+x = _lhs x (_rhs world)
 ------------ core code
 hello :: ()
 hello = _rhs ()
diff --git a/testdata/language-features/module/import07.out b/testdata/language-features/module/import07.out
index 31cb267f..531e24a2 100644
--- a/testdata/language-features/module/import07.out
+++ b/testdata/language-features/module/import07.out
@@ -1,8 +1,8 @@
 main is not found
 ------------ desugared source code
-hello = _rhs ()
+hello = _lhs hello (_rhs ())
 
-x = _rhs world
+x = _lhs x (_rhs world)
 ------------ core code
 hello :: ()
 hello = _rhs ()
diff --git a/testdata/language-features/module/import08.out b/testdata/language-features/module/import08.out
index e68b7bcd..fd3ee5b9 100644
--- a/testdata/language-features/module/import08.out
+++ b/testdata/language-features/module/import08.out
@@ -1,15 +1,15 @@
 main is not found
 ------------ desugared source code
-value = _rhs ()
+value = _lhs value (_rhs ())
 
 g :: Char
-g = _rhs greeting
+g = _lhs g (_rhs greeting)
 
 h :: String
-h = _rhs hello
+h = _lhs h (_rhs hello)
 
 w :: String
-w = _rhs world
+w = _lhs w (_rhs world)
 ------------ core code
 g :: Char
 g = _rhs 'G'
diff --git a/testdata/language-features/module/import09.out b/testdata/language-features/module/import09.out
index c8e689e5..3082c3ff 100644
--- a/testdata/language-features/module/import09.out
+++ b/testdata/language-features/module/import09.out
@@ -1,7 +1,7 @@
 main is not found
 ------------ desugared source code
 fun :: forall (a :: _) . a -> MyUnit -> MyUnit
-fun = \(_ :: _) (a :: _) -> hlistNilCase _ (_rhs ()) a
+fun = _lhs fun \(_ :: _) (a :: _) -> hlistNilCase _ (_rhs ()) a
 ------------ core code
 fun :: forall a . a -> MyUnit -> ()
 fun = \_ _ a -> hlistNilCase ' () (_rhs ()) a
diff --git a/testdata/language-features/module/import12.out b/testdata/language-features/module/import12.out
index 26a58bd3..760cc132 100644
--- a/testdata/language-features/module/import12.out
+++ b/testdata/language-features/module/import12.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-fun = _rhs hello
+fun = _lhs fun (_rhs hello)
 ------------ core code
 fun :: String
 fun = _rhs "hello"
diff --git a/testdata/language-features/module/import13.out b/testdata/language-features/module/import13.out
index 5a9791da..fd02626b 100644
--- a/testdata/language-features/module/import13.out
+++ b/testdata/language-features/module/import13.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-fun = _rhs hello
+fun = _lhs fun (_rhs hello)
 ------------ core code
 fun :: String
 fun = _rhs "hello"
diff --git a/testdata/language-features/module/import14.out b/testdata/language-features/module/import14.out
index a2feaea6..3b09db66 100644
--- a/testdata/language-features/module/import14.out
+++ b/testdata/language-features/module/import14.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-fun = _rhs hello
+fun = _lhs fun (_rhs hello)
 ------------ core code
 fun :: String
 fun = _rhs "hello"
diff --git a/testdata/language-features/module/import15.out b/testdata/language-features/module/import15.out
index 7e58a5c7..9cf8cd6f 100644
--- a/testdata/language-features/module/import15.out
+++ b/testdata/language-features/module/import15.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-fun = _rhs hello
+fun = _lhs fun (_rhs hello)
 ------------ core code
 fun :: String
 fun = _rhs "Hello"
diff --git a/testdata/language-features/pattern/pattern01.out b/testdata/language-features/pattern/pattern01.out
index b01ea25b..bbd1d94e 100644
--- a/testdata/language-features/pattern/pattern01.out
+++ b/testdata/language-features/pattern/pattern01.out
@@ -1,13 +1,21 @@
 main is not found
 ------------ desugared source code
 fun1
-  = \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '0') (fromInt 0 == a)
+  = _lhs
+    fun1
+    \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '0') (fromInt 0 == a)
 
-fun2 = \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '0') ("0" == a)
+fun2
+  = _lhs
+    fun2
+    \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '0') ("0" == a)
 
-fun3 = \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '0') ('0' == a)
+fun3
+  = _lhs
+    fun3
+    \(a :: _) -> case'Bool (\(_ :: _) -> _) (_rhs '_') (_rhs '0') ('0' == a)
 
-fun4 = \(a :: _) -> hlistNilCase _ (_rhs '0') a
+fun4 = _lhs fun4 \(a :: _) -> hlistNilCase _ (_rhs '0') a
 ------------ core code
 fun1 :: forall a . (Eq a, Num a) => a -> Char
 fun1
diff --git a/testdata/language-features/pattern/uncovered.out b/testdata/language-features/pattern/uncovered.out
index b461ff6e..f9952c69 100644
--- a/testdata/language-features/pattern/uncovered.out
+++ b/testdata/language-features/pattern/uncovered.out
@@ -1,89 +1,95 @@
 main is not found
 ------------ desugared source code
 f
-  = \(a :: _) (b :: _) (c :: _) -> case'Bool
-    (\(_ :: _) -> _)
-    (case'Bool
-      (\(_ :: _) -> _)
-      (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs (fromInt 1)) c)
-      (_rhs (fromInt 2))
-      a)
-    (case'Bool
+  = _lhs
+    f
+    \(a :: _) (b :: _) (c :: _) -> case'Bool
       (\(_ :: _) -> _)
-      (_rhs (fromInt 0))
-      (case'Bool (\(_ :: _) -> _) (_rhs (fromInt 1)) (_rhs undefined) a)
-      c)
-    b
+      (case'Bool
+        (\(_ :: _) -> _)
+        (case'Bool (\(_ :: _) -> _) (_rhs undefined) (_rhs (fromInt 1)) c)
+        (_rhs (fromInt 2))
+        a)
+      (case'Bool
+        (\(_ :: _) -> _)
+        (_rhs (fromInt 0))
+        (case'Bool (\(_ :: _) -> _) (_rhs (fromInt 1)) (_rhs undefined) a)
+        c)
+      b
 
 g
-  = \(a :: _) -> case'List
-    (\(_ :: _) -> _)
-    (_rhs undefined)
-    (\(b :: _) (c :: _) -> case'Bool
+  = _lhs
+    g
+    \(a :: _) -> case'List
       (\(_ :: _) -> _)
       (_rhs undefined)
-      (case'List
+      (\(b :: _) (c :: _) -> case'Bool
         (\(_ :: _) -> _)
         (_rhs undefined)
-        (\(d :: _) (e :: _) -> case'Bool
+        (case'List
           (\(_ :: _) -> _)
-          (case'List
+          (_rhs undefined)
+          (\(d :: _) (e :: _) -> case'Bool
             (\(_ :: _) -> _)
-            (_rhs undefined)
-            (\(f :: _) (g :: _) -> case'Bool
+            (case'List
               (\(_ :: _) -> _)
               (_rhs undefined)
-              (case'List
+              (\(f :: _) (g :: _) -> case'Bool
                 (\(_ :: _) -> _)
-                (_rhs False)
-                (\(_ :: _) (_ :: _) -> _rhs undefined)
-                g)
-              f)
-            e)
-          (_rhs undefined)
-          d)
-        c)
-      b)
-    a
+                (_rhs undefined)
+                (case'List
+                  (\(_ :: _) -> _)
+                  (_rhs False)
+                  (\(_ :: _) (_ :: _) -> _rhs undefined)
+                  g)
+                f)
+              e)
+            (_rhs undefined)
+            d)
+          c)
+        b)
+      a
 
 h
-  = \(a :: _) -> case'List
-    (\(_ :: _) -> _)
-    (_rhs undefined)
-    (\(b :: _) (c :: _) -> case'List
+  = _lhs
+    h
+    \(a :: _) -> case'List
       (\(_ :: _) -> _)
       (_rhs undefined)
-      (\(d :: _) (e :: _) -> case'Bool
+      (\(b :: _) (c :: _) -> case'List
         (\(_ :: _) -> _)
         (_rhs undefined)
-        (case'List
+        (\(d :: _) (e :: _) -> case'Bool
           (\(_ :: _) -> _)
+          (_rhs undefined)
           (case'List
             (\(_ :: _) -> _)
-            (_rhs undefined)
-            (\(f :: _) (g :: _) -> case'List
+            (case'List
               (\(_ :: _) -> _)
               (_rhs undefined)
-              (\(h :: _) (i :: _) -> case'Bool
+              (\(f :: _) (g :: _) -> case'List
                 (\(_ :: _) -> _)
-                (case'List
+                (_rhs undefined)
+                (\(h :: _) (i :: _) -> case'Bool
                   (\(_ :: _) -> _)
                   (case'List
                     (\(_ :: _) -> _)
-                    (_rhs True)
+                    (case'List
+                      (\(_ :: _) -> _)
+                      (_rhs True)
+                      (\(_ :: _) (_ :: _) -> _rhs undefined)
+                      g)
                     (\(_ :: _) (_ :: _) -> _rhs undefined)
-                    g)
-                  (\(_ :: _) (_ :: _) -> _rhs undefined)
-                  i)
-                (_rhs undefined)
-                h)
-              f)
-            c)
-          (\(_ :: _) (_ :: _) -> _rhs undefined)
-          e)
-        d)
-      b)
-    a
+                    i)
+                  (_rhs undefined)
+                  h)
+                f)
+              c)
+            (\(_ :: _) (_ :: _) -> _rhs undefined)
+            e)
+          d)
+        b)
+      a
 ------------ core code
 f :: forall a . Num a => Bool -> Bool -> Bool -> a
 f
diff --git a/testdata/language-features/pattern/unreachable.out b/testdata/language-features/pattern/unreachable.out
index e8991ac1..7b7df75d 100644
--- a/testdata/language-features/pattern/unreachable.out
+++ b/testdata/language-features/pattern/unreachable.out
@@ -1,6 +1,6 @@
 main is not found
 ------------ desugared source code
-f = \(_ :: _) -> _rhs "hello"
+f = _lhs f \(_ :: _) -> _rhs "hello"
 ------------ core code
 f :: forall a . a -> String
 f = \_ _ -> _rhs "hello"
diff --git a/testdata/language-features/recursion/simplerec01.out b/testdata/language-features/recursion/simplerec01.out
index f6732e0f..736caa77 100644
--- a/testdata/language-features/recursion/simplerec01.out
+++ b/testdata/language-features/recursion/simplerec01.out
@@ -1,11 +1,13 @@
 main is not found
 ------------ desugared source code
 fun
-  = \(a :: _) -> case'Bool
-    (\(_ :: _) -> _)
-    (_rhs (fun (fromInt 0)))
-    (_rhs 'a')
-    (fromInt 0 == a)
+  = _lhs
+    fun
+    \(a :: _) -> case'Bool
+      (\(_ :: _) -> _)
+      (_rhs (fun (fromInt 0)))
+      (_rhs 'a')
+      (fromInt 0 == a)
 ------------ core code
 fun :: forall a . (Num a, Eq a, Num a) => a -> Char
 fun
diff --git a/testdata/language-features/recursion/simplerec02.out b/testdata/language-features/recursion/simplerec02.out
index 39e52ba0..d80f3cfd 100644
--- a/testdata/language-features/recursion/simplerec02.out
+++ b/testdata/language-features/recursion/simplerec02.out
@@ -1,16 +1,20 @@
 main is not found
 ------------ desugared source code
 value
-  = _rhs
-    let
-      a
-        = primFix
-          \(b :: _) (c :: _) -> case'Bool
-            (\(_ :: _) -> _)
-            (_rhs (b (fromInt 0)))
-            (_rhs 'a')
-            (fromInt 0 == c)
-      in ()
+  = _lhs
+    value
+    (_rhs
+      let
+        a
+          = primFix
+            \(b :: _) -> _lhs
+              fun
+              \(c :: _) -> case'Bool
+                (\(_ :: _) -> _)
+                (_rhs (b (fromInt 0)))
+                (_rhs 'a')
+                (fromInt 0 == c)
+        in ())
 ------------ core code
 value :: ()
 value = _rhs ()
diff --git a/testdata/language-features/recursion/simplerec03.out b/testdata/language-features/recursion/simplerec03.out
index 32df69c1..031dbc8d 100644
--- a/testdata/language-features/recursion/simplerec03.out
+++ b/testdata/language-features/recursion/simplerec03.out
@@ -1,16 +1,20 @@
 main is not found
 ------------ desugared source code
 value
-  = _rhs
-    let
-      a
-        = primFix
-          \(b :: _) (c :: _) -> case'Bool
-            (\(_ :: _) -> _)
-            (_rhs (b (fromInt 0)))
-            (_rhs 'a')
-            (fromInt 0 == c)
-      in ()
+  = _lhs
+    value
+    (_rhs
+      let
+        a
+          = primFix
+            \(b :: _) -> _lhs
+              fun
+              \(c :: _) -> case'Bool
+                (\(_ :: _) -> _)
+                (_rhs (b (fromInt 0)))
+                (_rhs 'a')
+                (fromInt 0 == c)
+        in ())
 ------------ core code
 value :: ()
 value = _rhs ()
diff --git a/testdata/language-features/section/section01.out b/testdata/language-features/section/section01.out
index d99e803e..a06769e3 100644
--- a/testdata/language-features/section/section01.out
+++ b/testdata/language-features/section/section01.out
@@ -1,10 +1,10 @@
 main is not found
 ------------ desugared source code
-(!@!) = \(_ :: _) (_ :: _) -> _rhs ()
+(!@!) = _lhs (!@!) \(_ :: _) (_ :: _) -> _rhs ()
 
-value1 = \(a :: _) -> _rhs \(b :: _) -> a !@! b
+value1 = _lhs value1 \(a :: _) -> _rhs \(b :: _) -> a !@! b
 
-value2 = \(a :: _) -> _rhs \(b :: _) -> b !@! a
+value2 = _lhs value2 \(a :: _) -> _rhs \(b :: _) -> b !@! a
 ------------ core code
 !@! :: forall a b . a -> b -> ()
 !@! = \_ _ _ _ -> _rhs ()