1 files changed, 27 insertions, 0 deletions
diff --git a/testsuite/tests/stranal/should_compile/ins.hs b/testsuite/tests/stranal/should_compile/ins.hs
new file mode 100644
index 0000000000..a50320cefa
--- /dev/null
+++ b/testsuite/tests/stranal/should_compile/ins.hs
@@ -0,0 +1,27 @@
+-- !! TEST OF DEFACTORISATION FOR FUNCTIONS THAT DROP 
+-- !!             POLYMORPHIC VARIABLES
+
+module Test where
+data Boolean = FF | TT
+data Pair a b = MkPair a b
+data LList alpha = Nill | Conss alpha (LList alpha) 
+data Nat = Zero | Succ Nat
+data Tree x = Leaf x | Node (Tree x) (Tree x) 
+data A a = MkA a (A a) 
+
+append :: LList a -> LList a -> LList a
+append  xs ys  = case xs of
+                  Nill -> ys 
+                  Conss z zs  -> Conss z (append zs ys) 
+
+-- The following function drops @b@.
+
+flat :: Tree (Pair a b) -> LList a
+flat t =  case t of
+              Leaf (MkPair a b) -> Conss a Nill 
+              Node l r -> append (flat l) (flat r)
+
+fl :: Boolean -> LList Boolean
+fl x = flat (Leaf (MkPair TT Zero)) 
+
+