Allow declaring universe constraints at definition level.

Introduce a "+" modifier for universe and constraint declarations to
indicate that these can be extended in the final definition/proof.  By
default [Definition f] is equivalent to [Definition f@{+|+}], i.e
universes can be introduced and constraints as well. For [f@{}] or
[f@{i j}], the constraints can be extended, no universe introduced, to
maintain compatibility with existing developments. Use [f@{i j | }] to
indicate that no constraint (nor universe) can be introduced. These
kind of definitions could benefit from asynchronous processing.

Declarations of universe binders and constraints also works for
monomorphic definitions.

1 files changed, 32 insertions, 0 deletions

diff --git a/test-suite/success/polymorphism.v b/test-suite/success/polymorphism.v
index ecc988507c..0bd8bfe602 100644
--- a/test-suite/success/polymorphism.v
+++ b/test-suite/success/polymorphism.v
@@ -156,6 +156,38 @@ Polymorphic Definition twoprojs (d : dyn) := dyn_proof d = dyn_proof d.
 
 End structures.
 
+
+Module binders.
+
+  Definition foo@{i j | i < j, i < j} (A : Type@{i}) : Type@{j}.
+    exact A.
+  Defined.
+
+  Definition nomoreu@{i j | i < j} (A : Type@{i}) : Type@{j}.
+    pose(foo:=Type).
+    exact A.
+  Fail Defined.
+  Abort.
+
+  Polymorphic Definition moreu@{i j +} (A : Type@{i}) : Type@{j}.
+    pose(foo:=Type).
+    exact A.
+  Defined.
+
+  Check moreu@{_ _ _ _}.
+  
+  Fail Definition morec@{i j| } (A : Type@{i}) : Type@{j} := A.
+
+  (* By default constraints are extensible *)
+  Definition morec@{i j} (A : Type@{i}) : Type@{j} := A.
+
+  (* FIXME: not handled in proofs correctly yet *)
+  Lemma bar@{i j | } : Type@{i}.
+    exact Type@{j}.
+  Defined.
+  
+End binders.
+    
 Section cats.
   Local Set Universe Polymorphism.
   Require Import Utf8.