2 files changed, 61 insertions, 2 deletions
diff --git a/test-suite/failure/int31.v b/test-suite/failure/int31.v
new file mode 100644
index 00000000..b1d11224
--- /dev/null
+++ b/test-suite/failure/int31.v
@@ -0,0 +1,17 @@
+Require Import Int31 BigN.
+
+Open Scope int31_scope.
+
+(* This used to go through because of an unbalanced stack bug in the bytecode
+interpreter *)
+
+Lemma bad : False.
+assert (1 = 2).
+change 1 with (add31 (addmuldiv31 65 (add31 1 1) 2) 1).
+Fail vm_compute; reflexivity.
+(*
+discriminate.
+Qed.
+*)
+Abort.
+
diff --git a/test-suite/failure/positivity.v b/test-suite/failure/positivity.v
index 91de8733..8089de2b 100644
--- a/test-suite/failure/positivity.v
+++ b/test-suite/failure/positivity.v
@@ -5,5 +5,47 @@
 (*    //   *      This file is distributed under the terms of the       *)
 (*         *       GNU Lesser General Public License Version 2.1        *)
 (************************************************************************)
-Fail Inductive t : Set :=
-    c : (t -> nat) -> t.
+
+(* Negative occurrence *)
+Fail Inductive t : Type :=
+  c : (t -> nat) -> t.
+
+(* Non-strictely positive occurrence *)
+Fail Inductive t : Type :=
+  c : ((t -> nat) -> nat) -> t.
+
+(* Self-nested type (no proof of
+   soundness yet *)
+Fail Inductive t (A:Type) : Type :=
+  c : t (t A) -> t A.
+
+(* Nested inductive types *)
+
+Inductive pos (A:Type) :=
+  p : pos A -> pos A.
+
+Inductive nnpos (A:Type) :=
+  nnp : ((A -> nat) -> nat) -> nnpos A.
+
+Inductive neg (A:Type) :=
+  n : (A->neg A) -> neg A.
+
+Inductive arg : Type -> Prop :=
+  a : forall A, arg A -> arg A.
+
+(* Strictly covariant parameter: accepted. *)
+Fail Fail Inductive t :=
+  c : pos t -> t.
+
+(* Non-strictly covariant parameter: not
+   strictly positive. *)
+Fail Inductive t :=
+  c : nnpos t -> t.
+
+(* Contravariant parameter: not positive. *)
+Fail Inductive t :=
+  c : neg t -> t.
+
+(* Strict index: not positive. *)
+Fail Inductive t :=
+  c : arg t -> t.