47 files changed, 602 insertions, 190 deletions

diff --git a/testdata/language-features/adt/adt02.out b/testdata/language-features/adt/adt02.out
index 84ef7d80..992c314e 100644
--- a/testdata/language-features/adt/adt02.out
+++ b/testdata/language-features/adt/adt02.out
@@ -126,19 +126,19 @@ one2 :: Data2 -> Bool
 one2 = \a -> case'Data2 (\_ -> 'Bool) (\b _ _ -> _rhs b) a
 
 one3 :: forall a b c . Data3 a b c -> a
-one3 = \a _ _ b -> case'Data3 (\_ -> a) (\c _ _ -> _rhs c) b
+one3 = \a b c d -> case'Data3 (\_ -> a) (\e _ _ -> _rhs e) d
 
 thr2 :: Data2 -> Bool
 thr2 = \a -> case'Data2 (\_ -> 'Bool) (\_ _ b -> _rhs b) a
 
 thr3 :: forall a b c . Data3 a b c -> c
-thr3 = \_ _ a b -> case'Data3 (\_ -> a) (\_ _ c -> _rhs c) b
+thr3 = \a b c d -> case'Data3 (\_ -> c) (\_ _ e -> _rhs e) d
 
 two2 :: Data2 -> String
 two2 = \a -> case'Data2 (\_ -> 'String) (\_ b _ -> _rhs b) a
 
 two3 :: forall a b c . Data3 a b c -> b
-two3 = \_ a _ b -> case'Data3 (\_ -> a) (\_ c _ -> _rhs c) b
+two3 = \a b c d -> case'Data3 (\_ -> b) (\_ e _ -> _rhs e) d
 
 value1 :: Data1
 value1 = _rhs (Data1 True)
diff --git a/testdata/language-features/adt/adt05.out b/testdata/language-features/adt/adt05.out
index c44d22b9..aed76869 100644
--- a/testdata/language-features/adt/adt05.out
+++ b/testdata/language-features/adt/adt05.out
@@ -1,5 +1,5 @@
 main :: @Type -> forall a . Num a => Bool
-main = main
+main = \_ _ _ -> True
 ------------ desugared source code
 data TList (_ :: Type) :: Type where
     TEmpty :: forall a . TList a
@@ -47,10 +47,10 @@ case'TList
 case'TList = \_ a b c d -> <<case function of a type with 1 parameters>>
 
 isCons :: forall a . TList a -> Bool
-isCons = \_ a -> case'TList (\_ -> 'Bool) (_rhs False) (\_ _ -> _rhs True) a
+isCons = \a b -> case'TList (\_ -> 'Bool) (_rhs False) (\_ _ -> _rhs True) b
 
 isEmpty :: forall a . TList a -> Bool
-isEmpty = \_ a -> case'TList (\_ -> 'Bool) (_rhs True) (\_ _ -> _rhs False) a
+isEmpty = \a b -> case'TList (\_ -> 'Bool) (_rhs True) (\_ _ -> _rhs False) b
 
 main :: @Type -> forall a . Num a => Bool
 main = \_ _ _ -> _rhs True
diff --git a/testdata/language-features/as-pattern/as-pattern01.out b/testdata/language-features/as-pattern/as-pattern01.out
index 5b9c82cd..3e2c4116 100644
--- a/testdata/language-features/as-pattern/as-pattern01.out
+++ b/testdata/language-features/as-pattern/as-pattern01.out
@@ -1,5 +1,6 @@
 main :: forall a . (Eq a, Num (MatVecScalarElem a), Eq a, Num a) => Bool
-main = main
+main
+  = \b c d e f -> (b == c) (g (fromInt b f 3) (fromInt b f 1)) (fromInt b f 5)
 ------------ desugared source code
 f
   = _lhs
@@ -37,7 +38,7 @@ g
 main :: forall a . (Eq a, Num (MatVecScalarElem a), Eq a, Num a) => Bool
 main
   = \a b c d e -> _rhs
-    ((a == b) (g a c d e (fromInt a e 3) (fromInt a e 1)) (fromInt a e 5))
+    ((a == b) (g (fromInt a e 3) (fromInt a e 1)) (fromInt a e 5))
 ------------ tooltips
 testdata/language-features/as-pattern/as-pattern01.lc 1:1-1:2
     forall a . [a] -> [a]
diff --git a/testdata/language-features/as-pattern/as-pattern02.out b/testdata/language-features/as-pattern/as-pattern02.out
index 8a9f96bc..8b4ba9d5 100644
--- a/testdata/language-features/as-pattern/as-pattern02.out
+++ b/testdata/language-features/as-pattern/as-pattern02.out
@@ -4,7 +4,24 @@ main
       => forall b
         . (a ~ [b], Eq b, Num b)
           => forall c . Eq c => forall d . (c ~ [d], Eq d, Num d) => Bool
-main = main
+main
+  = \_ _ e _ f g _ _ h _ i j -> PrimAnd
+    (undefined
+      ([e] -> [e] -> 'Bool)
+      (primIfThenElse
+        [e]
+        ((e == f) (fromInt e g 0) (fromInt e g 0))
+        [fromInt e g 1]
+        [fromInt e g 0, fromInt e g 1])
+      [fromInt e g 1])
+    (undefined
+      ([h] -> [h] -> 'Bool)
+      (primIfThenElse
+        [h]
+        ((h == i) (fromInt h j 1) (fromInt h j 0))
+        []
+        [fromInt h j 1])
+      [fromInt h j 1])
 ------------ desugared source code
 f
   = _lhs
@@ -43,20 +60,9 @@ main
     (PrimAnd
       (undefined
         ([a] -> [a] -> 'Bool)
-        (primIfThenElse
-          [a]
-          ((a == b) (fromInt a c 0) (fromInt a c 0))
-          [fromInt a c 1]
-          [fromInt a c 0, fromInt a c 1])
+        (f [fromInt a c 0, fromInt a c 1])
         [fromInt a c 1])
-      (undefined
-        ([d] -> [d] -> 'Bool)
-        (primIfThenElse
-          [d]
-          ((d == e) (fromInt d f 1) (fromInt d f 0))
-          []
-          [fromInt d f 1])
-        [fromInt d f 1]))
+      (undefined ([d] -> [d] -> 'Bool) (f [fromInt d f 1]) [fromInt d f 1]))
 ------------ tooltips
 testdata/language-features/as-pattern/as-pattern02.lc 3:1-3:2
     forall a . (Eq a, Num a) => [a] -> [a]
diff --git a/testdata/language-features/basic-list/dotdot01.out b/testdata/language-features/basic-list/dotdot01.out
index 9b85b6a5..c564f228 100644
--- a/testdata/language-features/basic-list/dotdot01.out
+++ b/testdata/language-features/basic-list/dotdot01.out
@@ -4,7 +4,7 @@ main = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0]
 main = _lhs main (_rhs (fromTo (fromInt 1) (fromInt 10)))
 ------------ core code
 main :: [Float]
-main = _rhs [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0]
+main = _rhs (1.0 : fromTo (1.0 + 1.0) 10.0)
 ------------ tooltips
 testdata/language-features/basic-list/dotdot01.lc 2:1-2:5
     [Float]
diff --git a/testdata/language-features/basic-list/listcomp01.out b/testdata/language-features/basic-list/listcomp01.out
index ace40823..0c20b420 100644
--- a/testdata/language-features/basic-list/listcomp01.out
+++ b/testdata/language-features/basic-list/listcomp01.out
@@ -3,7 +3,7 @@ main is not found
 value = _lhs value (_rhs (concatMap (\(_ :: _) -> [()]) [(), (), (), ()]))
 ------------ core code
 value :: [()]
-value = _rhs [(), (), (), ()]
+value = _rhs (() : [] ++ foldr (++) [] (map (\_ -> [()]) [(), (), ()]))
 ------------ tooltips
 testdata/language-features/basic-list/listcomp01.lc 1:1-1:6
     [()]
diff --git a/testdata/language-features/basic-list/listcomp02.out b/testdata/language-features/basic-list/listcomp02.out
index 18619ff6..528fef4a 100644
--- a/testdata/language-features/basic-list/listcomp02.out
+++ b/testdata/language-features/basic-list/listcomp02.out
@@ -8,7 +8,7 @@ l :: [()]
 l = _rhs [(), (), (), ()]
 
 value :: [()]
-value = _rhs [(), (), (), ()]
+value = _rhs (() : [] ++ foldr (++) [] (map (\a -> [a]) [(), (), ()]))
 ------------ tooltips
 testdata/language-features/basic-list/listcomp02.lc 1:1-1:2
     [()]
diff --git a/testdata/language-features/basic-list/listcomp04.out b/testdata/language-features/basic-list/listcomp04.out
index 4d43ac94..dfd8bd3c 100644
--- a/testdata/language-features/basic-list/listcomp04.out
+++ b/testdata/language-features/basic-list/listcomp04.out
@@ -9,7 +9,11 @@ l :: [()]
 l = _rhs [(), (), (), ()]
 
 value :: [()]
-value = _rhs [(), (), (), (), (), (), (), (), (), (), (), (), (), (), (), ()]
+value
+  = _rhs
+    (()
+      : [] ++ foldr (++) [] (map (\_ -> [()]) [(), (), ()])
+        ++ foldr (++) [] (map (\_ -> concatMap ' () ' () (\_ -> [()]) l) [(), (), ()]))
 ------------ tooltips
 testdata/language-features/basic-list/listcomp04.lc 1:1-1:2
     [()]
diff --git a/testdata/language-features/basic-list/listcomp05.out b/testdata/language-features/basic-list/listcomp05.out
index c9e56736..46e18270 100644
--- a/testdata/language-features/basic-list/listcomp05.out
+++ b/testdata/language-features/basic-list/listcomp05.out
@@ -11,7 +11,7 @@ value
         [(), ()]))
 ------------ core code
 value :: [()]
-value = _rhs [(), ()]
+value = _rhs (u : [] ++ foldr (++) [] (map (\_ -> [u]) [()]))
 ------------ tooltips
 testdata/language-features/basic-list/listcomp05.lc 1:1-1:6
     [()]
diff --git a/testdata/language-features/basic-list/listcomp06.out b/testdata/language-features/basic-list/listcomp06.out
index cf4e2b31..b0e13efb 100644
--- a/testdata/language-features/basic-list/listcomp06.out
+++ b/testdata/language-features/basic-list/listcomp06.out
@@ -22,10 +22,14 @@ value2
         [(), ()]))
 ------------ core code
 value1 :: [()]
-value1 = _rhs [(), ()]
+value1
+  = _rhs
+    (u : [] ++ foldr (++) [] (map (\_ -> primIfThenElse [' ()] True [u] []) [()]))
 
 value2 :: [()]
-value2 = _rhs [(), ()]
+value2
+  = _rhs
+    (u : [] ++ foldr (++) [] (map (\_ -> primIfThenElse [' ()] True [u] []) [()]))
 ------------ tooltips
 testdata/language-features/basic-list/listcomp06.lc 1:1-1:7
     [()]
diff --git a/testdata/language-features/basic-list/listcomp07.out b/testdata/language-features/basic-list/listcomp07.out
index 2f4d633a..cbabbc48 100644
--- a/testdata/language-features/basic-list/listcomp07.out
+++ b/testdata/language-features/basic-list/listcomp07.out
@@ -40,13 +40,19 @@ value3
         [(), ()]))
 ------------ core code
 value1 :: [()]
-value1 = _rhs [(), ()]
+value1
+  = _rhs
+    (u : [] ++ foldr (++) [] (map (\_ -> primIfThenElse [' ()] True [u] []) [()]))
 
 value2 :: [()]
-value2 = _rhs [(), ()]
+value2
+  = _rhs
+    (u : [] ++ foldr (++) [] (map (\_ -> primIfThenElse [' ()] True [u] []) [()]))
 
 value3 :: [()]
-value3 = _rhs [(), ()]
+value3
+  = _rhs
+    (u : [] ++ foldr (++) [] (map (\_ -> primIfThenElse [' ()] True [u] []) [()]))
 ------------ tooltips
 testdata/language-features/basic-list/listcomp07.lc 1:1-1:7
     [()]
diff --git a/testdata/language-features/basic-values/def01.out b/testdata/language-features/basic-values/def01.out
index 6564e1b8..eba795a8 100644
--- a/testdata/language-features/basic-values/def01.out
+++ b/testdata/language-features/basic-values/def01.out
@@ -7,10 +7,10 @@ fun1 = _lhs fun1 \(_ :: _) -> _rhs (fromInt 1)
 fun2 = _lhs fun2 \(_ :: _) (_ :: _) (_ :: _) (_ :: _) (_ :: _) -> _rhs 'c'
 ------------ core code
 fun1 :: forall a b . Num b => a -> b
-fun1 = \_ a b _ -> _rhs (fromInt a b 1)
+fun1 = \a b c _ -> _rhs (fromInt b c 1)
 
 fun2 :: forall a b c d e . a -> b -> c -> d -> e -> Char
-fun2 = \_ _ _ _ _ _ _ _ _ _ -> _rhs 'c'
+fun2 = \a b c d e _ _ _ _ _ -> _rhs 'c'
 
 unit :: ()
 unit = _rhs ()
diff --git a/testdata/language-features/basic-values/def04.out b/testdata/language-features/basic-values/def04.out
index 127129e9..d4fbfa4e 100644
--- a/testdata/language-features/basic-values/def04.out
+++ b/testdata/language-features/basic-values/def04.out
@@ -28,11 +28,11 @@ fun
 
 fun2 :: forall a b . (Eq a, Num a, Eq a, Num a) => a -> b -> Char
 fun2
-  = \a _ b c d e f _ -> case'Bool
+  = \a b c d e f g _ -> case'Bool
     (\_ -> 'Char)
-    (case'Bool (\_ -> 'Char) (_rhs '_') (_rhs '2') ((a == b) (fromInt a c 2) f))
+    (case'Bool (\_ -> 'Char) (_rhs '_') (_rhs '2') ((a == c) (fromInt a d 2) g))
     (_rhs '1')
-    ((a == d) (fromInt a e 1) f)
+    ((a == e) (fromInt a f 1) g)
 ------------ tooltips
 testdata/language-features/basic-values/def04.lc 1:1-1:4
     forall a . (Eq a, Num a, Eq a, Num a) => a -> Char
diff --git a/testdata/language-features/basic-values/deforder03.out b/testdata/language-features/basic-values/deforder03.out
index cf40c23e..66cb3c71 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 = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
+value = _lhs value (_rhs let a = (); b = 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 767b8a9b..17a9a408 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 = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
+value = _lhs value (_rhs let a = (); b = 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 7345785e..abc83591 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 = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
+value = _lhs value (_rhs let a = (); b = 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 2a0ead81..c44eec77 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 = _lhs value (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs a) in '1')
+value = _lhs value (_rhs let a = (); b = 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 f4f17b40..689c921a 100644
--- a/testdata/language-features/basic-values/fixity01.out
+++ b/testdata/language-features/basic-values/fixity01.out
@@ -17,16 +17,16 @@ infixr 6 >>>>
 infixr 6 funR
 ------------ core code
 <<<< :: forall a b . a -> b -> a
-<<<< = \_ _ a _ -> _rhs a
+<<<< = \a b c _ -> _rhs c
 
 >>>> :: forall a b . a -> b -> b
->>>> = \_ _ _ a -> _rhs a
+>>>> = \a b _ c -> _rhs c
 
 funL :: forall a b . a -> b -> a
-funL = \_ _ a _ -> _rhs a
+funL = \a b c _ -> _rhs c
 
 funR :: forall a b . a -> b -> a
-funR = \_ _ a _ -> _rhs a
+funR = \a b c _ -> _rhs c
 ------------ tooltips
 testdata/language-features/basic-values/fixity01.lc 1:1-1:5
     forall a b . a -> b -> a
diff --git a/testdata/language-features/basic-values/fixity02.out b/testdata/language-features/basic-values/fixity02.out
index b07707af..1dbf5728 100644
--- a/testdata/language-features/basic-values/fixity02.out
+++ b/testdata/language-features/basic-values/fixity02.out
@@ -55,16 +55,16 @@ funValue7
 funValue8 = _lhs funValue8 (_rhs (() `funL` 'c' `funL` "hi" `funL` 1.2 :: ()))
 ------------ core code
 <@ :: forall a b . a -> b -> a
-<@ = \_ _ a _ -> _rhs a
+<@ = \a b c _ -> _rhs c
 
 @> :: forall a b . a -> b -> b
-@> = \_ _ _ a -> _rhs a
+@> = \a b _ c -> _rhs c
 
 funL :: forall a b . a -> b -> a
-funL = \_ _ a _ -> _rhs a
+funL = \a b c _ -> _rhs c
 
 funR :: forall a b . a -> b -> b
-funR = \_ _ _ a -> _rhs a
+funR = \a b _ c -> _rhs c
 
 funValue1 :: Float
 funValue1 = _rhs 1.2
diff --git a/testdata/language-features/basic-values/infix01.out b/testdata/language-features/basic-values/infix01.out
index ced45621..55d5dad5 100644
--- a/testdata/language-features/basic-values/infix01.out
+++ b/testdata/language-features/basic-values/infix01.out
@@ -5,10 +5,10 @@ fun = _lhs fun \(_ :: _) (_ :: _) -> _rhs ()
 value = _lhs value \(a :: _) (b :: _) -> _rhs (a `fun` b)
 ------------ core code
 fun :: forall a b . a -> b -> ()
-fun = \_ _ _ _ -> _rhs ()
+fun = \a b _ _ -> _rhs ()
 
 value :: forall a b . a -> b -> ()
-value = \_ _ _ _ -> _rhs ()
+value = \a b _ _ -> _rhs ()
 ------------ tooltips
 testdata/language-features/basic-values/infix01.lc 1:1-1:4
     forall a b . a -> b -> ()
diff --git a/testdata/language-features/basic-values/infix02.out b/testdata/language-features/basic-values/infix02.out
index 888f4d9f..c32a0ce7 100644
--- a/testdata/language-features/basic-values/infix02.out
+++ b/testdata/language-features/basic-values/infix02.out
@@ -5,10 +5,10 @@ fun = _lhs fun \(_ :: _) (_ :: _) (_ :: _) -> _rhs ()
 value = _lhs value \(a :: _) (b :: _) -> _rhs (a `fun` b)
 ------------ core code
 fun :: forall a b c . a -> b -> c -> ()
-fun = \_ _ _ _ _ _ -> _rhs ()
+fun = \a b c _ _ _ -> _rhs ()
 
 value :: forall a b c . a -> b -> c -> ()
-value = \a b c d e -> _rhs (fun a b c d e)
+value = \a b c d e -> _rhs (fun d e)
 ------------ tooltips
 testdata/language-features/basic-values/infix02.lc 1:1-1:4
     forall a b c . a -> b -> c -> ()
diff --git a/testdata/language-features/basic-values/lambda01.out b/testdata/language-features/basic-values/lambda01.out
index 0a07171f..1476c47f 100644
--- a/testdata/language-features/basic-values/lambda01.out
+++ b/testdata/language-features/basic-values/lambda01.out
@@ -15,17 +15,17 @@ fun4
         -> ())
 ------------ core code
 fun1 :: forall a . a -> ()
-fun1 = \_ -> _rhs \_ -> ()
+fun1 = \a -> _rhs \_ -> ()
 
 fun2 :: forall a . a -> ()
-fun2 = \_ -> _rhs \_ -> ()
+fun2 = \a -> _rhs \_ -> ()
 
 fun3 :: forall a . a -> ()
-fun3 = \_ -> _rhs \_ -> ()
+fun3 = \a -> _rhs \_ -> ()
 
 fun4
   :: forall a b c d e f g h i . a -> b -> c -> d -> e -> f -> g -> h -> i -> ()
-fun4 = \_ _ _ _ _ _ _ _ _ -> _rhs \_ _ _ _ _ _ _ _ _ -> ()
+fun4 = \a b c d e f g h i -> _rhs \_ _ _ _ _ _ _ _ _ -> ()
 ------------ tooltips
 testdata/language-features/basic-values/lambda01.lc 1:1-1:5
     forall a . a -> ()
diff --git a/testdata/language-features/basic-values/lambda03.out b/testdata/language-features/basic-values/lambda03.out
index f9ddcaa4..50af2ae5 100644
--- a/testdata/language-features/basic-values/lambda03.out
+++ b/testdata/language-features/basic-values/lambda03.out
@@ -5,10 +5,10 @@ fun1 = _lhs fun1 (_rhs \(_ :: _) (a :: _) (_ :: _) -> a)
 fun2 = _lhs fun2 \(a :: _) -> _rhs \(_ :: _) (_ :: _) (_ :: _) -> a
 ------------ core code
 fun1 :: forall a b c . a -> b -> c -> b
-fun1 = \_ _ _ -> _rhs \_ a _ -> a
+fun1 = \a b c -> _rhs \_ d _ -> d
 
 fun2 :: forall a b c d . a -> b -> c -> d -> a
-fun2 = \_ _ _ _ a -> _rhs \_ _ _ -> a
+fun2 = \a b c d e -> _rhs \_ _ _ -> e
 ------------ tooltips
 testdata/language-features/basic-values/lambda03.lc 1:1-1:5
     forall a b c . a -> b -> c -> b
diff --git a/testdata/language-features/basic-values/let01.out b/testdata/language-features/basic-values/let01.out
index 7d40e348..bd59a558 100644
--- a/testdata/language-features/basic-values/let01.out
+++ b/testdata/language-features/basic-values/let01.out
@@ -1,21 +1,14 @@
 main is not found
 ------------ desugared source code
-value1 = _lhs value1 (_rhs let a = _lhs x (_rhs (fromInt 1)) in fromInt 1)
+value1 = _lhs value1 (_rhs let a = fromInt 1 in fromInt 1)
 
-value2 = _lhs value2 (_rhs let a = _lhs x (_rhs (fromInt 1)) in fromInt 1)
+value2 = _lhs value2 (_rhs let a = fromInt 1 in fromInt 1)
 
-value3
-  = _lhs
-    value3
-    (_rhs let a = _lhs x (_rhs (fromInt 1)); b = _lhs y (_rhs 'c') in fromInt 1)
+value3 = _lhs value3 (_rhs let a = fromInt 1; b = 'c' in fromInt 1)
 
-value4 = _lhs value4 (_rhs let a = _lhs x (_rhs (fromInt 1)) in fromInt 1)
+value4 = _lhs value4 (_rhs let a = fromInt 1 in fromInt 1)
 
-value5
-  = _lhs
-    value5
-    (_rhs
-      let a = _lhs x (_rhs (fromInt 1)); b = _lhs y (_rhs (fromInt 2)) in fromInt 1)
+value5 = _lhs value5 (_rhs let a = fromInt 1; b = 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 f9de03b4..574a8d36 100644
--- a/testdata/language-features/basic-values/let02.out
+++ b/testdata/language-features/basic-values/let02.out
@@ -5,15 +5,7 @@ value
     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')
+        a = (); b = let d = 'A' in (); c = let e = (); f = fromInt 1; g = "hello" in 'B'
         in ())
 ------------ core code
 value :: ()
diff --git a/testdata/language-features/basic-values/operator01.out b/testdata/language-features/basic-values/operator01.out
index 3b6dd323..817d1b5f 100644
--- a/testdata/language-features/basic-values/operator01.out
+++ b/testdata/language-features/basic-values/operator01.out
@@ -9,16 +9,16 @@ main is not found
 ($$$) = _lhs ($$$) \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 #$# :: forall a b . a -> b -> ()
-#$# = \_ _ _ _ -> _rhs ()
+#$# = \a b _ _ -> _rhs ()
 
 $$# :: forall a b . a -> b -> ()
-$$# = \_ _ _ _ -> _rhs ()
+$$# = \a b _ _ -> _rhs ()
 
 $$$ :: forall a b . a -> b -> ()
-$$$ = \_ _ _ _ -> _rhs ()
+$$$ = \a b _ _ -> _rhs ()
 
 $$$# :: forall a b . a -> b -> ()
-$$$# = \_ _ _ _ -> _rhs ()
+$$$# = \a b _ _ -> _rhs ()
 ------------ tooltips
 testdata/language-features/basic-values/operator01.lc 1:3-1:6
     forall a b . a -> b -> ()
diff --git a/testdata/language-features/basic-values/shadowing01.out b/testdata/language-features/basic-values/shadowing01.out
index b1288270..502ad96f 100644
--- a/testdata/language-features/basic-values/shadowing01.out
+++ b/testdata/language-features/basic-values/shadowing01.out
@@ -5,23 +5,12 @@ value
     value
     (_rhs
       let
-        a = _lhs x (_rhs 'A');
-        b = _lhs y (_rhs "hello");
+        a = 'A';
+        b = "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 ())
+          = let
+            d = fromInt 1; e = 2.12; f = let g = (); h = 'C'; i = 3.12 in "world"
+            in ()
         in '7')
 ------------ core code
 value :: Char
diff --git a/testdata/language-features/basic-values/shadowing02.out b/testdata/language-features/basic-values/shadowing02.out
index 7edd4cef..aa0b9af2 100644
--- a/testdata/language-features/basic-values/shadowing02.out
+++ b/testdata/language-features/basic-values/shadowing02.out
@@ -9,27 +9,13 @@ value2
     value2
     (_rhs
       let
-        a = _lhs x (_rhs 'A');
-        b = _lhs y (_rhs "hello");
-        c = _lhs w (_rhs (fromInt 123));
+        a = 'A';
+        b = "hello";
+        c = 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 ())
+          = let
+            e = fromInt 1; f = 2.12; g = let h = (); i = 'C'; j = 3.12; k = c in world
+            in ()
         in '7')
 ------------ core code
 c :: forall a . Num a => a
diff --git a/testdata/language-features/basic-values/shadowing03.out b/testdata/language-features/basic-values/shadowing03.out
index f796c908..cb7d1050 100644
--- a/testdata/language-features/basic-values/shadowing03.out
+++ b/testdata/language-features/basic-values/shadowing03.out
@@ -3,7 +3,7 @@ main is not found
 x = _lhs x \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 x :: forall a b . a -> b -> ()
-x = \_ _ _ _ -> _rhs ()
+x = \a b _ _ -> _rhs ()
 ------------ tooltips
 testdata/language-features/basic-values/shadowing03.lc 1:1-1:2
     forall a b . a -> b -> ()
diff --git a/testdata/language-features/basic-values/shadowing04.out b/testdata/language-features/basic-values/shadowing04.out
index 59d10c41..042c221d 100644
--- a/testdata/language-features/basic-values/shadowing04.out
+++ b/testdata/language-features/basic-values/shadowing04.out
@@ -3,7 +3,7 @@ main is not found
 __ = _lhs __ \(_ :: _) (_ :: _) -> _rhs ()
 ------------ core code
 __ :: forall a b . a -> b -> ()
-__ = \_ _ _ _ -> _rhs ()
+__ = \a b _ _ -> _rhs ()
 ------------ tooltips
 testdata/language-features/basic-values/shadowing04.lc 1:1-1:3
     forall a b . a -> b -> ()
diff --git a/testdata/language-features/basic-values/typesig05.out b/testdata/language-features/basic-values/typesig05.out
index 7ca5e11a..fc1da409 100644
--- a/testdata/language-features/basic-values/typesig05.out
+++ b/testdata/language-features/basic-values/typesig05.out
@@ -15,10 +15,10 @@ value4 :: String
 value4 = _lhs value4 (_rhs (funR 'a' "b"))
 ------------ core code
 funL :: forall a b . a -> b -> a
-funL = \_ _ a _ -> _rhs a
+funL = \a b c _ -> _rhs c
 
 funR :: forall a b . a -> b -> b
-funR = \_ _ _ a -> _rhs a
+funR = \a b _ c -> _rhs c
 
 value1 :: Char
 value1 = _rhs 'a'
diff --git a/testdata/language-features/basic-values/typesig06.out b/testdata/language-features/basic-values/typesig06.out
index 6cc32fea..04783c47 100644
--- a/testdata/language-features/basic-values/typesig06.out
+++ b/testdata/language-features/basic-values/typesig06.out
@@ -9,10 +9,10 @@ value1 = _lhs value1 (_rhs ("hi" <@ 1.2 :: String))
 value2 = _lhs value2 (_rhs ("hi" `funL` 1.2 :: String))
 ------------ core code
 <@ :: forall a b . a -> b -> a
-<@ = \_ _ a _ -> _rhs a
+<@ = \a b c _ -> _rhs c
 
 funL :: forall a b . a -> b -> a
-funL = \_ _ a _ -> _rhs a
+funL = \a b c _ -> _rhs c
 
 value1 :: String
 value1 = _rhs "hi"
diff --git a/testdata/language-features/basic-values/where01.out b/testdata/language-features/basic-values/where01.out
index 3b56a3c4..45cdab5f 100644
--- a/testdata/language-features/basic-values/where01.out
+++ b/testdata/language-features/basic-values/where01.out
@@ -1,14 +1,14 @@
 main is not found
 ------------ desugared source code
-value1 = _lhs value1 (_rhs let a = _lhs x (_rhs ()) in ())
+value1 = _lhs value1 (_rhs let a = () in ())
 
-value2 = _lhs value2 (_rhs let a = _lhs x (_rhs ()) in a)
+value2 = _lhs value2 (_rhs let a = () in a)
 
-value3 = _lhs value3 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
+value3 = _lhs value3 (_rhs let a = (); b = () in a)
 
-value4 = _lhs value4 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in b)
+value4 = _lhs value4 (_rhs let a = (); b = () in b)
 
-value5 = _lhs value5 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
+value5 = _lhs value5 (_rhs let a = (); b = () in a)
 
 value6 = _lhs value6 (_rhs ())
 
@@ -16,13 +16,11 @@ value7 = _lhs value7 (_rhs ())
 
 value8 = _lhs value8 (_rhs ())
 
-value9 = _lhs value9 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
+value9 = _lhs value9 (_rhs let a = (); b = () in a)
 
-value10
-  = _lhs value10 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
+value10 = _lhs value10 (_rhs let a = (); b = () in a)
 
-value11
-  = _lhs value11 (_rhs let a = _lhs x (_rhs ()); b = _lhs y (_rhs ()) in a)
+value11 = _lhs value11 (_rhs let a = (); b = () 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 3095e9d3..0c247314 100644
--- a/testdata/language-features/basic-values/where04.out
+++ b/testdata/language-features/basic-values/where04.out
@@ -1,13 +1,10 @@
 main is not found
 ------------ desugared source code
-value1
-  = _lhs value1 (_rhs let a = _lhs x (_rhs let b = _lhs y (_rhs ()) in b) in a)
+value1 = _lhs value1 (_rhs let a = let b = () in b in a)
 
-value2
-  = _lhs value2 (_rhs let a = _lhs x (_rhs let b = _lhs y (_rhs ()) in b) in a)
+value2 = _lhs value2 (_rhs let a = let b = () in b in a)
 
-value3
-  = _lhs value3 (_rhs let a = _lhs x (_rhs let b = _lhs y (_rhs ()) in b) in a)
+value3 = _lhs value3 (_rhs let a = let b = () 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 0dc19f61..768de934 100644
--- a/testdata/language-features/basic-values/where05.out
+++ b/testdata/language-features/basic-values/where05.out
@@ -4,44 +4,28 @@ value1
   = _lhs
     value1
     (_rhs
-      ((\(a :: _) -> case'Bool
-          (\(_ :: _) -> _)
-          ()
-          (let b = _lhs x (_rhs ()) in b)
-          (fromInt 1 == a))
+      ((\(a :: _) -> case'Bool (\(_ :: _) -> _) () (let b = () in b) (fromInt 1 == a))
         (fromInt 1)))
 
 value2
   = _lhs
     value2
     (_rhs
-      ((\(a :: _) -> case'Bool
-          (\(_ :: _) -> _)
-          ()
-          (let b = _lhs x (_rhs ()) in b)
-          (fromInt 1 == a))
+      ((\(a :: _) -> case'Bool (\(_ :: _) -> _) () (let b = () in b) (fromInt 1 == a))
         (fromInt 1)))
 
 value3
   = _lhs
     value3
     (_rhs
-      ((\(a :: _) -> case'Bool
-          (\(_ :: _) -> _)
-          ()
-          (let b = _lhs x (_rhs ()) in b)
-          (fromInt 1 == a))
+      ((\(a :: _) -> case'Bool (\(_ :: _) -> _) () (let b = () in b) (fromInt 1 == a))
         (fromInt 1)))
 
 value4
   = _lhs
     value4
     (_rhs
-      let a = _lhs x (_rhs ()) in (\(b :: _) -> case'Bool
-          (\(_ :: _) -> _)
-          ()
-          a
-          (fromInt 1 == b))
+      let a = () in (\(b :: _) -> case'Bool (\(_ :: _) -> _) () a (fromInt 1 == b))
         (fromInt 1))
 ------------ core code
 value1 :: forall a . (Eq a, Num a) => ()
diff --git a/testdata/language-features/basic-values/wildcard01.out b/testdata/language-features/basic-values/wildcard01.out
index b462aac7..4f954c87 100644
--- a/testdata/language-features/basic-values/wildcard01.out
+++ b/testdata/language-features/basic-values/wildcard01.out
@@ -3,7 +3,7 @@ main is not found
 funUnit = _lhs funUnit \(_ :: _) -> _rhs ()
 ------------ core code
 funUnit :: forall a . a -> ()
-funUnit = \_ _ -> _rhs ()
+funUnit = \a _ -> _rhs ()
 ------------ tooltips
 testdata/language-features/basic-values/wildcard01.lc 1:1-1:8
     forall a . a -> ()
diff --git a/testdata/language-features/pattern/caseWhere.out b/testdata/language-features/pattern/caseWhere.out
index 3c090334..0a5e69c4 100644
--- a/testdata/language-features/pattern/caseWhere.out
+++ b/testdata/language-features/pattern/caseWhere.out
@@ -5,12 +5,7 @@ main
   = _lhs
     main
     (_rhs
-      ((\(a :: _) -> let b = _lhs c (_rhs a) in case'Bool
-          (\(_ :: _) -> _)
-          undefined
-          a
-          b)
-        True))
+      ((\(a :: _) -> let b = a in case'Bool (\(_ :: _) -> _) undefined a b) True))
 ------------ core code
 main :: Bool
 main = _rhs True
diff --git a/testdata/language-features/pattern/unreachable.out b/testdata/language-features/pattern/unreachable.out
index 7b7df75d..8eb5d0db 100644
--- a/testdata/language-features/pattern/unreachable.out
+++ b/testdata/language-features/pattern/unreachable.out
@@ -3,7 +3,7 @@ main is not found
 f = _lhs f \(_ :: _) -> _rhs "hello"
 ------------ core code
 f :: forall a . a -> String
-f = \_ _ -> _rhs "hello"
+f = \a _ -> _rhs "hello"
 ------------ tooltips
 testdata/language-features/pattern/unreachable.lc 4:1-4:2
     forall a . a -> String
diff --git a/testdata/language-features/pattern/viewPattern.out b/testdata/language-features/pattern/viewPattern.out
index f8fdb6d9..654f8467 100644
--- a/testdata/language-features/pattern/viewPattern.out
+++ b/testdata/language-features/pattern/viewPattern.out
@@ -9,7 +9,7 @@ main
     (_rhs ((\(a :: _) -> case'Bool (\(_ :: _) -> _) undefined True (id a)) True))
 ------------ core code
 id :: forall a . a -> a
-id = \_ a -> _rhs a
+id = \a b -> _rhs b
 
 main :: Bool
 main = _rhs True
diff --git a/testdata/language-features/recursion/mutualConst.lc b/testdata/language-features/recursion/mutualConst.lc
index c7f83f18..526a14a7 100644
--- a/testdata/language-features/recursion/mutualConst.lc
+++ b/testdata/language-features/recursion/mutualConst.lc
@@ -1,9 +1,14 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+import Internals
 
-xy = (\x y -> ((1 :: Int): y, 1: x)) (fst xy) (snd xy)
+fst (x, y) = x
+snd (x, y) = y
+
+xy = (\x y -> (False: y, True: x)) (fst xy) (snd xy)
 
 (x, y) = xy
 
 main = case x of
-    1: 1: 1: _ -> True
+    False: True: False: _ -> True
 
 
diff --git a/testdata/language-features/recursion/mutualConst.out b/testdata/language-features/recursion/mutualConst.out
index 4791ed55..34d37bc7 100644
--- a/testdata/language-features/recursion/mutualConst.out
+++ b/testdata/language-features/recursion/mutualConst.out
@@ -1 +1,194 @@
-True
\ No newline at end of file
+main :: Bool
+main = True
+------------ desugared source code
+fst
+  = _lhs
+    fst
+    \(a :: _) -> hlistConsCase
+      _
+      (\(b :: _) (c :: _) -> hlistConsCase
+        _
+        (\(_ :: _) (d :: _) -> hlistNilCase _ (_rhs b) d)
+        c)
+      a
+
+snd
+  = _lhs
+    snd
+    \(a :: _) -> hlistConsCase
+      _
+      (\(_ :: _) (b :: _) -> hlistConsCase
+        _
+        (\(c :: _) (d :: _) -> hlistNilCase _ (_rhs c) d)
+        b)
+      a
+
+xy
+  = primFix
+    \(a :: _) -> _lhs
+      xy
+      (_rhs ((\(b :: _) (c :: _) -> (False : c, True : b)) (fst a) (snd a)))
+
+_y_x = _lhs _y_x (_rhs xy)
+
+y
+  = _lhs
+    y
+    (_rhs
+      ((\(a :: _) -> hlistConsCase
+          _
+          (\(_ :: _) (b :: _) -> hlistConsCase
+            _
+            (\(c :: _) (d :: _) -> hlistNilCase _ c d)
+            b)
+          a)
+        _y_x))
+
+x
+  = _lhs
+    x
+    (_rhs
+      ((\(a :: _) -> hlistConsCase
+          _
+          (\(b :: _) (c :: _) -> hlistConsCase
+            _
+            (\(_ :: _) (d :: _) -> hlistNilCase _ b d)
+            c)
+          a)
+        _y_x))
+
+main
+  = _lhs
+    main
+    (_rhs
+      ((\(a :: _) -> case'List
+          (\(_ :: _) -> _)
+          undefined
+          (\(b :: _) (c :: _) -> case'Bool
+            (\(_ :: _) -> _)
+            (case'List
+              (\(_ :: _) -> _)
+              undefined
+              (\(d :: _) (e :: _) -> case'Bool
+                (\(_ :: _) -> _)
+                undefined
+                (case'List
+                  (\(_ :: _) -> _)
+                  undefined
+                  (\(f :: _) (_ :: _) -> case'Bool (\(_ :: _) -> _) True undefined f)
+                  e)
+                d)
+              c)
+            undefined
+            b)
+          a)
+        x))
+------------ core code
+_y_x :: ([Bool], [Bool])
+_y_x = _rhs (False : snd xy, True : fst xy)
+
+fst :: forall a b . (a, b) -> a
+fst
+  = \a b c -> hlistConsCase
+    a
+    [b]
+    a
+    (\d e -> hlistConsCase b [] a (\_ f -> hlistNilCase a (_rhs d) f) e)
+    c
+
+main :: Bool
+main = _rhs True
+
+snd :: forall a b . (a, b) -> b
+snd
+  = \a b c -> hlistConsCase
+    a
+    [b]
+    b
+    (\_ d -> hlistConsCase b [] b (\e f -> hlistNilCase b (_rhs e) f) d)
+    c
+
+x :: [Bool]
+x = _rhs (False : snd xy)
+
+xy :: ([Bool], [Bool])
+xy = primFix _ \a -> _rhs (False : snd a, True : fst a)
+
+y :: [Bool]
+y = _rhs (True : fst xy)
+------------ tooltips
+testdata/language-features/recursion/mutualConst.lc 4:1-4:4
+    forall a b . (a, b) -> a
+testdata/language-features/recursion/mutualConst.lc 4:14-4:15
+    _k | _h | _d
+testdata/language-features/recursion/mutualConst.lc 5:1-5:4
+    forall a b . (a, b) -> b
+testdata/language-features/recursion/mutualConst.lc 5:14-5:15
+    _f | _c | _c
+testdata/language-features/recursion/mutualConst.lc 7:1-7:3
+    ([Bool], [Bool])
+testdata/language-features/recursion/mutualConst.lc 7:6-7:44
+    [Bool] -> ([Bool], [Bool])
+testdata/language-features/recursion/mutualConst.lc 7:6-7:53
+    ([Bool], [Bool])
+testdata/language-features/recursion/mutualConst.lc 7:15-7:34
+    ([Bool], [Bool])
+testdata/language-features/recursion/mutualConst.lc 7:16-7:21
+    Bool
+testdata/language-features/recursion/mutualConst.lc 7:16-7:22
+    [Bool] -> [Bool]
+testdata/language-features/recursion/mutualConst.lc 7:16-7:24
+    [Bool]
+testdata/language-features/recursion/mutualConst.lc 7:21-7:22
+    forall a . a -> [a] -> [a]
+testdata/language-features/recursion/mutualConst.lc 7:23-7:24
+    _c
+testdata/language-features/recursion/mutualConst.lc 7:26-7:30
+    Bool
+testdata/language-features/recursion/mutualConst.lc 7:26-7:31
+    [Bool] -> [Bool]
+testdata/language-features/recursion/mutualConst.lc 7:26-7:33
+    [Bool] | (([Bool]))
+testdata/language-features/recursion/mutualConst.lc 7:30-7:31
+    forall a . a -> [a] -> [a]
+testdata/language-features/recursion/mutualConst.lc 7:32-7:33
+    _e
+testdata/language-features/recursion/mutualConst.lc 7:37-7:40
+    forall a b . (a, b) -> a
+testdata/language-features/recursion/mutualConst.lc 7:37-7:43
+    _b
+testdata/language-features/recursion/mutualConst.lc 7:41-7:43
+    _d
+testdata/language-features/recursion/mutualConst.lc 7:46-7:49
+    forall a b . (a, b) -> b
+testdata/language-features/recursion/mutualConst.lc 7:46-7:52
+    [Bool]
+testdata/language-features/recursion/mutualConst.lc 7:50-7:52
+    ([Bool], [Bool])
+testdata/language-features/recursion/mutualConst.lc 9:2-9:3
+    _k | _h | _d | [Bool]
+testdata/language-features/recursion/mutualConst.lc 9:2-9:6
+    ([Bool], [Bool]) | ([Bool], [Bool]) | ([Bool], [Bool])
+testdata/language-features/recursion/mutualConst.lc 9:5-9:6
+    _f | _c | _c | [Bool]
+testdata/language-features/recursion/mutualConst.lc 9:10-9:12
+    ([Bool], [Bool])
+testdata/language-features/recursion/mutualConst.lc 11:1-11:5
+    Bool
+testdata/language-features/recursion/mutualConst.lc 11:8-12:34
+    Bool
+testdata/language-features/recursion/mutualConst.lc 11:13-11:14
+    [Bool]
+testdata/language-features/recursion/mutualConst.lc 12:30-12:34
+    Bool | Bool | Bool | Bool | Bool | Bool
+------------ warnings
+Uncovered pattern(s) at testdata/language-features/recursion/mutualConst.lc:11:13:
+main = case x of
+            ^
+Missing case(s):
+     []
+     [False]
+     (False : False : _)
+     [False, True]
+     (False : True : True : _)
+     (True : _)
\ No newline at end of file
diff --git a/testdata/language-features/recursion/mutualFunc.lc b/testdata/language-features/recursion/mutualFunc.lc
new file mode 100644
index 00000000..2f3a524e
--- /dev/null
+++ b/testdata/language-features/recursion/mutualFunc.lc
@@ -0,0 +1,11 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+import Internals
+
+f True = g False
+f False = g True
+
+g True = True
+g x = f x
+
+main = f True
+
diff --git a/testdata/language-features/recursion/mutualFunc.out b/testdata/language-features/recursion/mutualFunc.out
new file mode 100644
index 00000000..6dd3f158
--- /dev/null
+++ b/testdata/language-features/recursion/mutualFunc.out
@@ -0,0 +1,107 @@
+main :: Bool
+main = True
+------------ desugared source code
+_g_f
+  = primFix
+    \(a :: _) -> let
+      b = a;
+      c
+        = (\(e :: _) -> hlistConsCase
+            _
+            (\(_ :: _) (f :: _) -> hlistConsCase
+              _
+              (\(g :: _) (h :: _) -> hlistNilCase _ g h)
+              f)
+            e)
+          b;
+      d
+        = (\(i :: _) -> hlistConsCase
+            _
+            (\(j :: _) (k :: _) -> hlistConsCase
+              _
+              (\(_ :: _) (l :: _) -> hlistNilCase _ j l)
+              k)
+            i)
+          b
+      in (_lhs g \(m :: _) -> case'Bool (\(_ :: _) -> _) (_rhs (c m)) (_rhs True) m
+    , _lhs
+      f
+      \(n :: _) -> case'Bool (\(_ :: _) -> _) (_rhs (d True)) (_rhs (d False)) n)
+
+_f_g = _g_f
+
+f
+  = (\(a :: _) -> hlistConsCase
+      _
+      (\(_ :: _) (b :: _) -> hlistConsCase
+        _
+        (\(c :: _) (d :: _) -> hlistNilCase _ c d)
+        b)
+      a)
+    _f_g
+
+g
+  = (\(a :: _) -> hlistConsCase
+      _
+      (\(b :: _) (c :: _) -> hlistConsCase
+        _
+        (\(_ :: _) (d :: _) -> hlistNilCase _ b d)
+        c)
+      a)
+    _f_g
+
+main = _lhs main (_rhs (f True))
+------------ core code
+_f_g :: (Bool -> Bool, Bool -> Bool)
+_f_g = primFix _ \a -> <<1st constructor of 'HList>>
+
+_g_f :: (Bool -> Bool, Bool -> Bool)
+_g_f = primFix _ \a -> <<1st constructor of 'HList>>
+
+f :: Bool -> Bool
+f = \a -> case'Bool (\_ -> 'Bool) (_rhs True) (_rhs True) a
+
+g :: Bool -> Bool
+g = \a -> case'Bool (\_ -> 'Bool) (_rhs (f a)) (_rhs True) a
+
+main :: Bool
+main = _rhs True
+------------ tooltips
+testdata/language-features/recursion/mutualFunc.lc 4:1-4:2
+    _f | _c | _c | _f | _c | _c | Bool -> Bool
+testdata/language-features/recursion/mutualFunc.lc 4:1-7:2
+    _b | _e | (_e, _d) | (Bool -> Bool, Bool -> Bool) | (Bool -> Bool
+    , Bool -> Bool) | (Bool -> Bool, Bool -> Bool) | (Bool -> Bool
+    , Bool -> Bool) | (Bool -> Bool, Bool -> Bool)
+testdata/language-features/recursion/mutualFunc.lc 4:10-4:11
+    Bool -> _a
+testdata/language-features/recursion/mutualFunc.lc 4:10-4:17
+    _a
+testdata/language-features/recursion/mutualFunc.lc 4:10-5:17
+    Bool -> _a | ((Bool -> _a))
+testdata/language-features/recursion/mutualFunc.lc 4:10-8:10
+    (Bool -> Bool, Bool -> _a)
+testdata/language-features/recursion/mutualFunc.lc 4:12-4:17
+    Bool
+testdata/language-features/recursion/mutualFunc.lc 5:11-5:12
+    _i
+testdata/language-features/recursion/mutualFunc.lc 5:13-5:17
+    Bool
+testdata/language-features/recursion/mutualFunc.lc 7:1-7:2
+    _k | _h | _d | _k | _h | _d | Bool -> Bool
+testdata/language-features/recursion/mutualFunc.lc 7:10-7:14
+    Bool
+testdata/language-features/recursion/mutualFunc.lc 7:10-8:10
+    Bool -> Bool
+testdata/language-features/recursion/mutualFunc.lc 8:7-8:8
+    _h
+testdata/language-features/recursion/mutualFunc.lc 8:9-8:10
+    _f
+testdata/language-features/recursion/mutualFunc.lc 10:1-10:5
+    Bool
+testdata/language-features/recursion/mutualFunc.lc 10:8-10:9
+    Bool -> Bool
+testdata/language-features/recursion/mutualFunc.lc 10:8-10:14
+    Bool
+testdata/language-features/recursion/mutualFunc.lc 10:10-10:14
+    Bool
\ No newline at end of file
diff --git a/testdata/language-features/recursion/mutualRec.lc b/testdata/language-features/recursion/mutualRec.lc
index c9ae6135..9a9422de 100644
--- a/testdata/language-features/recursion/mutualRec.lc
+++ b/testdata/language-features/recursion/mutualRec.lc
@@ -1,8 +1,10 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+import Internals
 
-x = 2: y
-y = 1: x
+x = False: y
+y = True: x
 
-main = case (x :: [Int]) of
-    2: 1: 2: _ -> True
+main = case x of
+    False: True: False: _ -> True
 
 
diff --git a/testdata/language-features/recursion/mutualRec.out b/testdata/language-features/recursion/mutualRec.out
index 4791ed55..885bd1ba 100644
--- a/testdata/language-features/recursion/mutualRec.out
+++ b/testdata/language-features/recursion/mutualRec.out
@@ -1 +1,139 @@
-True
\ No newline at end of file
+main :: Bool
+main = True
+------------ desugared source code
+_y_x
+  = primFix
+    \(a :: _) -> let
+      b = a;
+      c
+        = (\(e :: _) -> hlistConsCase
+            _
+            (\(_ :: _) (f :: _) -> hlistConsCase
+              _
+              (\(g :: _) (h :: _) -> hlistNilCase _ g h)
+              f)
+            e)
+          b;
+      d
+        = (\(i :: _) -> hlistConsCase
+            _
+            (\(j :: _) (k :: _) -> hlistConsCase
+              _
+              (\(_ :: _) (l :: _) -> hlistNilCase _ j l)
+              k)
+            i)
+          b
+      in (_lhs y (_rhs (True : c)), _lhs x (_rhs (False : d)))
+
+_x_y = _y_x
+
+x
+  = (\(a :: _) -> hlistConsCase
+      _
+      (\(_ :: _) (b :: _) -> hlistConsCase
+        _
+        (\(c :: _) (d :: _) -> hlistNilCase _ c d)
+        b)
+      a)
+    _x_y
+
+y
+  = (\(a :: _) -> hlistConsCase
+      _
+      (\(b :: _) (c :: _) -> hlistConsCase
+        _
+        (\(_ :: _) (d :: _) -> hlistNilCase _ b d)
+        c)
+      a)
+    _x_y
+
+main
+  = _lhs
+    main
+    (_rhs
+      ((\(a :: _) -> case'List
+          (\(_ :: _) -> _)
+          undefined
+          (\(b :: _) (c :: _) -> case'Bool
+            (\(_ :: _) -> _)
+            (case'List
+              (\(_ :: _) -> _)
+              undefined
+              (\(d :: _) (e :: _) -> case'Bool
+                (\(_ :: _) -> _)
+                undefined
+                (case'List
+                  (\(_ :: _) -> _)
+                  undefined
+                  (\(f :: _) (_ :: _) -> case'Bool (\(_ :: _) -> _) True undefined f)
+                  e)
+                d)
+              c)
+            undefined
+            b)
+          a)
+        x))
+------------ core code
+_x_y :: ([Bool], [Bool])
+_x_y = primFix _ \a -> <<1st constructor of 'HList>>
+
+_y_x :: ([Bool], [Bool])
+_y_x = primFix _ \a -> <<1st constructor of 'HList>>
+
+main :: Bool
+main = _rhs True
+
+x :: [Bool]
+x = _rhs (False : y)
+
+y :: [Bool]
+y = _rhs (True : x)
+------------ tooltips
+testdata/language-features/recursion/mutualRec.lc 4:1-4:2
+    _f | _c | _c | _f | _c | _c | [Bool]
+testdata/language-features/recursion/mutualRec.lc 4:1-5:2
+    _b | _e | (_e, _d) | ([Bool], [Bool]) | ([Bool], [Bool]) | ([Bool]
+    , [Bool]) | ([Bool], [Bool]) | ([Bool], [Bool])
+testdata/language-features/recursion/mutualRec.lc 4:5-4:10
+    Bool
+testdata/language-features/recursion/mutualRec.lc 4:5-4:11
+    [Bool] -> [Bool]
+testdata/language-features/recursion/mutualRec.lc 4:5-4:13
+    [Bool] | (([Bool]))
+testdata/language-features/recursion/mutualRec.lc 4:5-5:12
+    ([Bool], [Bool])
+testdata/language-features/recursion/mutualRec.lc 4:10-4:11
+    forall a . a -> [a] -> [a]
+testdata/language-features/recursion/mutualRec.lc 4:12-4:13
+    _e
+testdata/language-features/recursion/mutualRec.lc 5:1-5:2
+    _k | _h | _d | _k | _h | _d | [Bool]
+testdata/language-features/recursion/mutualRec.lc 5:5-5:9
+    Bool
+testdata/language-features/recursion/mutualRec.lc 5:5-5:10
+    [Bool] -> [Bool]
+testdata/language-features/recursion/mutualRec.lc 5:5-5:12
+    [Bool]
+testdata/language-features/recursion/mutualRec.lc 5:9-5:10
+    forall a . a -> [a] -> [a]
+testdata/language-features/recursion/mutualRec.lc 5:11-5:12
+    _d
+testdata/language-features/recursion/mutualRec.lc 7:1-7:5
+    Bool
+testdata/language-features/recursion/mutualRec.lc 7:8-8:34
+    Bool
+testdata/language-features/recursion/mutualRec.lc 7:13-7:14
+    [Bool]
+testdata/language-features/recursion/mutualRec.lc 8:30-8:34
+    Bool | Bool | Bool | Bool | Bool | Bool
+------------ warnings
+Uncovered pattern(s) at testdata/language-features/recursion/mutualRec.lc:7:13:
+main = case x of
+            ^
+Missing case(s):
+     []
+     [False]
+     (False : False : _)
+     [False, True]
+     (False : True : True : _)
+     (True : _)
\ No newline at end of file
diff --git a/testdata/language-features/recursion/simplerec01.out b/testdata/language-features/recursion/simplerec01.out
index 736caa77..823d544e 100644
--- a/testdata/language-features/recursion/simplerec01.out
+++ b/testdata/language-features/recursion/simplerec01.out
@@ -1,18 +1,19 @@
 main is not found
 ------------ desugared source code
 fun
-  = _lhs
-    fun
-    \(a :: _) -> case'Bool
-      (\(_ :: _) -> _)
-      (_rhs (fun (fromInt 0)))
-      (_rhs 'a')
-      (fromInt 0 == a)
+  = primFix
+    \(a :: _) -> _lhs
+      fun
+      \(b :: _) -> case'Bool
+        (\(_ :: _) -> _)
+        (_rhs (a (fromInt 0)))
+        (_rhs 'a')
+        (fromInt 0 == b)
 ------------ core code
 fun :: forall a . (Num a, Eq a, Num a) => a -> Char
 fun
   = \a b c d -> primFix
-    (a -> 'Char)
+    _
     \e f -> case'Bool
       (\_ -> 'Char)
       (_rhs (e (fromInt a b 0)))
diff --git a/testdata/language-features/section/section01.out b/testdata/language-features/section/section01.out
index a06769e3..0252cce5 100644
--- a/testdata/language-features/section/section01.out
+++ b/testdata/language-features/section/section01.out
@@ -7,13 +7,13 @@ value1 = _lhs value1 \(a :: _) -> _rhs \(b :: _) -> a !@! b
 value2 = _lhs value2 \(a :: _) -> _rhs \(b :: _) -> b !@! a
 ------------ core code
 !@! :: forall a b . a -> b -> ()
-!@! = \_ _ _ _ -> _rhs ()
+!@! = \a b _ _ -> _rhs ()
 
 value1 :: forall a b . a -> b -> ()
-value1 = \a b c -> _rhs \d -> ()
+value1 = \a b c -> _rhs \d -> c !@! d
 
 value2 :: forall a b . a -> b -> ()
-value2 = \a b c -> _rhs \d -> ()
+value2 = \a b c -> _rhs \d -> d !@! c
 ------------ tooltips
 testdata/language-features/section/section01.lc 1:3-1:6
     forall a b . a -> b -> ()