Merge PR #79: Let the kernel assume that a (co-)inductive type is positive.

2 files changed, 22 insertions, 4 deletions

diff --git a/checker/cic.mli b/checker/cic.mli
index 00ac2f56c..469cf8d4c 100644
--- a/checker/cic.mli
+++ b/checker/cic.mli
@@ -212,6 +212,15 @@ type constant_def =
 
 type constant_universes = Univ.universe_context
 
+(** The [typing_flags] are instructions to the type-checker which
+    modify its behaviour. The typing flags used in the type-checking
+    of a constant are tracked in their {!constant_body} so that they
+    can be displayed to the user. *)
+type typing_flags = {
+  check_guarded : bool; (** If [false] then fixed points and co-fixed
+                            points are assumed to be total. *)
+}
+
 type constant_body = {
     const_hyps : section_context; (** New: younger hyp at top *)
     const_body : constant_def;
@@ -220,7 +229,9 @@ type constant_body = {
     const_polymorphic : bool; (** Is it polymorphic or not *)
     const_universes : constant_universes;
     const_proj : projection_body option;
-    const_inline_code : bool }
+    const_inline_code : bool;
+    const_typing_flags : typing_flags;
+}
 
 (** {6 Representation of mutual inductive types } *)
 
@@ -316,6 +327,8 @@ type mutual_inductive_body = {
 
     mind_private : bool option; (** allow pattern-matching: Some true ok, Some false blocked *)
 
+    mind_checked_positive : bool; (** [false] when the mutual-inductive was assumed to be well-founded, bypassing the positivity checker.  *)
+
 (** {8 Data for native compilation } *)
 
     mind_native_name : native_name ref; (** status of the code (linked or not, and where) *)
diff --git a/checker/values.ml b/checker/values.ml
index 19cbb5060..dd29f6fbe 100644
--- a/checker/values.ml
+++ b/checker/values.ml
@@ -13,7 +13,7 @@
 To ensure this file is up-to-date, 'make' now compares the md5 of cic.mli
 with a copy we maintain here:
 
-MD5 9f7fd499f812b6548a55f7067e6a9d06 checker/cic.mli
+MD5 7d7963269852d32324e10aa77beb938d  checker/cic.mli
 
 *)
 
@@ -213,6 +213,9 @@ let v_projbody =
 	    v_tuple "proj_eta" [|v_constr;v_constr|];
 	    v_constr|]
 
+let v_typing_flags =
+  v_tuple "typing_flags" [|v_bool|]
+
 let v_cb = v_tuple "constant_body"
   [|v_section_ctxt;
     v_cst_def;
@@ -221,7 +224,8 @@ let v_cb = v_tuple "constant_body"
     v_bool;
     v_context;
     Opt v_projbody;
-    v_bool|]
+    v_bool;
+    v_typing_flags|]
 
 let v_recarg = v_sum "recarg" 1 (* Norec *)
   [|[|v_ind|] (* Mrec *);[|v_ind|] (* Imbr *)|]
@@ -270,7 +274,8 @@ let v_ind_pack = v_tuple "mutual_inductive_body"
     v_rctxt;
     v_bool;
     v_context;
-    Opt v_bool|]
+    Opt v_bool;
+    v_bool|]
 
 let v_with =
   Sum ("with_declaration_body",0,