1 files changed, 19 insertions, 0 deletions
diff --git a/test-suite/success/Case6.v b/test-suite/success/Case6.v
new file mode 100644
index 00000000..a262251e
--- /dev/null
+++ b/test-suite/success/Case6.v
@@ -0,0 +1,19 @@
+Parameter ff: (n,m:nat)~n=m -> ~(S n)=(S m).
+Parameter discr_r : (n:nat) ~(O=(S n)).
+Parameter discr_l : (n:nat) ~((S n)=O).
+
+Fixpoint eqdec [n:nat] : (m:nat) n=m \/ ~n=m := 
+[m:nat]
+ <[n,m:nat] n=m \/ ~n=m>Cases n m of
+      O   O   => (or_introl ? ~O=O (refl_equal ? O))
+
+   |  O (S x) => (or_intror O=(S x) ? (discr_r x))
+
+   | (S x) O  => (or_intror ? ~(S x)=O (discr_l x))
+
+   | ((S x) as N) ((S y) as M) =>  
+      <N=M\/~N=M>Cases (eqdec x y) of
+        (or_introl h) => (or_introl  ? ~N=M (f_equal nat nat S x y h))
+      | (or_intror h) => (or_intror N=M ? (ff x y h))   
+      end
+ end.