Merge branch 'v8.5' into trunk

15 files changed, 205 insertions, 56 deletions

diff --git a/CHANGES b/CHANGES
index 1de3c25d8..7956db6f5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -82,14 +82,38 @@ Tools
 Changes from V8.5pl1 to V8.5pl2
 ===============================
 
-Bugfixes
+Critical bugfix
+- Checksums of .vo files dependencies were not correctly checked.
+
+Other bugfixes
 
+- #4097: more efficient occur-check in presence of primitive projections
+- #4398: type_scope used consistently in "match goal".
+- #4450: eauto does not work with polymorphic lemmas
 - #4677: fix alpha-conversion in notations needing eta-expansion.
 - Fully preserve initial order of hypotheses in "Regular Subst Tactic" mode.
 - #4644: a regression in unification.
-- #4777: printing inefficiency with implicit arguments
+- #4725: Function (Error: Conversion test raised an anomaly) and Program
+  (Error: Cannot infer this placeholder of type)
+- #4747: Problem building Coq 8.5pl1 with OCaml 4.03.0: Fatal warnings
 - #4752: CoqIDE crash on files not ended by ".v".
-- #4398: type_scope used consistently in "match goal".
+- #4777: printing inefficiency with implicit arguments
+- #4818: "Admitted" fails due to undefined universe anomaly after calling
+  "destruct"
+- #4823: remote counter: avoid thread race on sockets
+- #4881: synchronizing "Declare Implicit Tactic" with backtrack.
+- #4882: anomaly with Declare Implicit Tactic on hole of type with evars
+- Fix use of "Declare Implicit Tactic" in refine.
+  triggered by CoqIDE
+
+Universes
+- Disallow silently dropping universe instances applied to variables
+  (forward compatible)
+- Allow explicit universe instances on notations, when they can apply
+  to the head reference of their expansion.
+
+Build infrastructure
+- New update on how to find camlp5 binary and library at configure time.
 
 Changes from V8.5 to V8.5pl1
 ============================
diff --git a/interp/constrintern.ml b/interp/constrintern.ml
index 470eb8324..1c50253d9 100644
--- a/interp/constrintern.ml
+++ b/interp/constrintern.ml
@@ -741,7 +741,13 @@ let string_of_ty = function
   | Method -> "meth"
   | Variable -> "var"
 
-let intern_var genv (ltacvars,ntnvars) namedctx loc id =
+let gvar (loc, id) us = match us with
+| None -> GVar (loc, id)
+| Some _ ->
+  user_err_loc (loc, "", str "Variable " ++ pr_id id ++
+    str " cannot have a universe instance")
+
+let intern_var genv (ltacvars,ntnvars) namedctx loc id us =
   (* Is [id] an inductive type potentially with implicit *)
   try
     let ty,expl_impls,impls,argsc = Id.Map.find id genv.impls in
@@ -749,21 +755,21 @@ let intern_var genv (ltacvars,ntnvars) namedctx loc id =
       (fun id -> CRef (Ident (loc,id),None), Some (loc,ExplByName id)) expl_impls in
     let tys = string_of_ty ty in
     Dumpglob.dump_reference loc "<>" (Id.to_string id) tys;
-    GVar (loc,id), make_implicits_list impls, argsc, expl_impls
+    gvar (loc,id) us, make_implicits_list impls, argsc, expl_impls
   with Not_found ->
   (* Is [id] bound in current term or is an ltac var bound to constr *)
   if Id.Set.mem id genv.ids || Id.Set.mem id ltacvars.ltac_vars
   then
-    GVar (loc,id), [], [], []
+    gvar (loc,id) us, [], [], []
   (* Is [id] a notation variable *)
   else if Id.Map.mem id ntnvars
   then
-    (set_var_scope loc id true genv ntnvars; GVar (loc,id), [], [], [])
+    (set_var_scope loc id true genv ntnvars; gvar (loc,id) us, [], [], [])
   (* Is [id] the special variable for recursive notations *)
   else if Id.equal id ldots_var
   then if Id.Map.is_empty ntnvars
     then error_ldots_var loc
-    else GVar (loc,id), [], [], []
+    else gvar (loc,id) us, [], [], []
   else if Id.Set.mem id ltacvars.ltac_bound then
     (* Is [id] bound to a free name in ltac (this is an ltac error message) *)
     user_err_loc (loc,"intern_var",
@@ -778,10 +784,10 @@ let intern_var genv (ltacvars,ntnvars) namedctx loc id =
 	let impls = implicits_of_global ref in
 	let scopes = find_arguments_scope ref in
 	Dumpglob.dump_reference loc "<>" (string_of_qualid (Decls.variable_secpath id)) "var";
-	GRef (loc, ref, None), impls, scopes, []
+	GRef (loc, ref, us), impls, scopes, []
       with e when CErrors.noncritical e ->
 	(* [id] a goal variable *)
-	GVar (loc,id), [], [], []
+	gvar (loc,id) us, [], [], []
 
 let find_appl_head_data c =
   match c with
@@ -843,9 +849,12 @@ let intern_qualid loc qid intern env lvar us args =
       let c = match us, c with
       | None, _ -> c
       | Some _, GRef (loc, ref, None) -> GRef (loc, ref, us)
+      | Some _, GApp (loc, GRef (loc', ref, None), arg) ->
+         GApp (loc, GRef (loc', ref, us), arg)
       | Some _, _ ->
         user_err_loc (loc, "", str "Notation " ++ pr_qualid qid ++
-          str " cannot have a universe instance")
+          str " cannot have a universe instance, its expanded head
+               does not start with a reference")
       in
       c, projapp, args2
 
@@ -864,7 +873,7 @@ let intern_applied_reference intern env namedctx (_, ntnvars as lvar) us args =
       let x, imp, scopes, l = find_appl_head_data r in
 	(x,imp,scopes,l), args2
   | Ident (loc, id) ->
-      try intern_var env lvar namedctx loc id, args
+      try intern_var env lvar namedctx loc id us, args
       with Not_found ->
       let qid = qualid_of_ident id in
       try
@@ -874,7 +883,7 @@ let intern_applied_reference intern env namedctx (_, ntnvars as lvar) us args =
       with Not_found ->
 	(* Extra allowance for non globalizing functions *)
 	if !interning_grammar || env.unb then
-	  (GVar (loc,id), [], [], []), args
+	  (gvar (loc,id) us, [], [], []), args
 	else error_global_not_found_loc loc qid
 
 let interp_reference vars r =
diff --git a/ltac/extratactics.ml4 b/ltac/extratactics.ml4
index 2ee9a6c98..be47293fc 100644
--- a/ltac/extratactics.ml4
+++ b/ltac/extratactics.ml4
@@ -337,11 +337,18 @@ END
 (**********************************************************************)
 (* Refine                                                             *)
 
+let constr_flags = {
+  Pretyping.use_typeclasses = true;
+  Pretyping.use_unif_heuristics = true;
+  Pretyping.use_hook = Some Pfedit.solve_by_implicit_tactic;
+  Pretyping.fail_evar = false;
+  Pretyping.expand_evars = true }
+
 let refine_tac ist simple c =
   Proofview.Goal.nf_enter { enter = begin fun gl ->
     let concl = Proofview.Goal.concl gl in
     let env = Proofview.Goal.env gl in
-    let flags = Pretyping.all_no_fail_flags in
+    let flags = constr_flags in
     let expected_type = Pretyping.OfType concl in
     let c = Pretyping.type_uconstr ~flags ~expected_type ist c in
     let update = { run = fun sigma -> c.delayed env sigma } in
@@ -517,11 +524,29 @@ VERNAC COMMAND EXTEND AddStepr CLASSIFIED AS SIDEFF
     [ add_transitivity_lemma false t ]
 END
 
+let cache_implicit_tactic (_,tac) = match tac with
+  | Some tac -> Pfedit.declare_implicit_tactic (Tacinterp.eval_tactic tac)
+  | None -> Pfedit.clear_implicit_tactic ()
+
+let subst_implicit_tactic (subst,tac) =
+  Option.map (Tacsubst.subst_tactic subst) tac
+
+let inImplicitTactic : glob_tactic_expr option -> obj =
+  declare_object {(default_object "IMPLICIT-TACTIC") with
+       open_function = (fun i o -> if Int.equal i 1 then cache_implicit_tactic o);
+       cache_function = cache_implicit_tactic;
+       subst_function = subst_implicit_tactic;
+       classify_function = (fun o -> Dispose)}
+
+let declare_implicit_tactic tac =
+  Lib.add_anonymous_leaf (inImplicitTactic (Some (Tacintern.glob_tactic tac)))
+
+let clear_implicit_tactic () =
+  Lib.add_anonymous_leaf (inImplicitTactic None)
+
 VERNAC COMMAND EXTEND ImplicitTactic CLASSIFIED AS SIDEFF
-| [ "Declare" "Implicit" "Tactic" tactic(tac) ] ->
-    [ Pfedit.declare_implicit_tactic (Tacinterp.interp tac) ]
-| [ "Clear" "Implicit" "Tactic" ] ->
-    [ Pfedit.clear_implicit_tactic () ]
+| [ "Declare" "Implicit" "Tactic" tactic(tac) ] -> [ declare_implicit_tactic tac ]
+| [ "Clear" "Implicit" "Tactic" ] -> [ clear_implicit_tactic () ]
 END
 
 
diff --git a/ltac/tacintern.ml b/ltac/tacintern.ml
index 00722ac28..455b871c8 100644
--- a/ltac/tacintern.ml
+++ b/ltac/tacintern.ml
@@ -424,7 +424,7 @@ let intern_hyp_location ist ((occs,id),hl) =
 (* Reads a pattern *)
 let intern_pattern ist ?(as_type=false) ltacvars = function
   | Subterm (b,ido,pc) ->
-      let (metas,pc) = intern_constr_pattern ist ~as_type:false ~ltacvars pc in
+      let (metas,pc) = intern_constr_pattern ist ~as_type ~ltacvars pc in
       ido, metas, Subterm (b,ido,pc)
   | Term pc ->
       let (metas,pc) = intern_constr_pattern ist ~as_type ~ltacvars pc in
@@ -446,7 +446,7 @@ let opt_cons accu = function
 | Some id -> Id.Set.add id accu
 
 (* Reads the hypotheses of a "match goal" rule *)
-let rec intern_match_goal_hyps ist ?(as_type=false) lfun = function
+let rec intern_match_goal_hyps ist lfun = function
   | (Hyp ((_,na) as locna,mp))::tl ->
       let ido, metas1, pat = intern_pattern ist ~as_type:true lfun mp in
       let lfun, metas2, hyps = intern_match_goal_hyps ist lfun tl in
@@ -455,7 +455,7 @@ let rec intern_match_goal_hyps ist ?(as_type=false) lfun = function
   | (Def ((_,na) as locna,mv,mp))::tl ->
       let ido, metas1, patv = intern_pattern ist ~as_type:false lfun mv in
       let ido', metas2, patt = intern_pattern ist ~as_type:true lfun mp in
-      let lfun, metas3, hyps = intern_match_goal_hyps ist ~as_type lfun tl in
+      let lfun, metas3, hyps = intern_match_goal_hyps ist lfun tl in
       let lfun' = name_cons (opt_cons (opt_cons lfun ido) ido') na in
       lfun', metas1@metas2@metas3, Def (locna,patv,patt)::hyps
   | [] -> lfun, [], []
@@ -564,7 +564,7 @@ and intern_tactic_seq onlytac ist = function
       ist.ltacvars, TacLetIn (isrec,l,intern_tactic onlytac ist' u)
 
   | TacMatchGoal (lz,lr,lmr) ->
-      ist.ltacvars, (TacMatchGoal(lz,lr, intern_match_rule onlytac ist ~as_type:true lmr))
+      ist.ltacvars, TacMatchGoal(lz,lr, intern_match_rule onlytac ist lmr)
   | TacMatch (lz,c,lmr) ->
       ist.ltacvars,
       TacMatch (lz,intern_tactic_or_tacarg ist c,intern_match_rule onlytac ist lmr)
@@ -668,18 +668,18 @@ and intern_tacarg strict onlytac ist = function
     TacGeneric arg
 
 (* Reads the rules of a Match Context or a Match *)
-and intern_match_rule onlytac ist ?(as_type=false) = function
+and intern_match_rule onlytac ist = function
   | (All tc)::tl ->
-      All (intern_tactic onlytac ist tc) :: (intern_match_rule onlytac ist ~as_type tl)
+      All (intern_tactic onlytac ist tc) :: (intern_match_rule onlytac ist tl)
   | (Pat (rl,mp,tc))::tl ->
       let {ltacvars=lfun; genv=env} = ist in
-      let lfun',metas1,hyps = intern_match_goal_hyps ist ~as_type lfun rl in
-      let ido,metas2,pat = intern_pattern ist ~as_type lfun mp in
+      let lfun',metas1,hyps = intern_match_goal_hyps ist lfun rl in
+      let ido,metas2,pat = intern_pattern ist lfun mp in
       let fold accu x = Id.Set.add x accu in
       let ltacvars = List.fold_left fold (opt_cons lfun' ido) metas1 in
       let ltacvars = List.fold_left fold ltacvars metas2 in
       let ist' = { ist with ltacvars } in
-      Pat (hyps,pat,intern_tactic onlytac ist' tc) :: (intern_match_rule onlytac ist ~as_type tl)
+      Pat (hyps,pat,intern_tactic onlytac ist' tc) :: (intern_match_rule onlytac ist tl)
   | [] -> []
 
 and intern_genarg ist (GenArg (Rawwit wit, x)) =
diff --git a/pretyping/evarsolve.ml b/pretyping/evarsolve.ml
index 62700aef3..338ac4300 100644
--- a/pretyping/evarsolve.ml
+++ b/pretyping/evarsolve.ml
@@ -212,30 +212,29 @@ let restrict_instance evd evk filter argsv =
 open Context.Rel.Declaration
 let noccur_evar env evd evk c =
   let cache = ref Int.Set.empty (* cache for let-ins *) in
-  let rec occur_rec (k, env as acc) c =
+  let rec occur_rec check_types (k, env as acc) c =
   match kind_of_term c with
   | Evar (evk',args' as ev') ->
       (match safe_evar_value evd ev' with
-       | Some c -> occur_rec acc c
+       | Some c -> occur_rec check_types acc c
        | None ->
            if Evar.equal evk evk' then raise Occur
-           else Array.iter (occur_rec acc) args')
+           else (if check_types then
+                   occur_rec false acc (existential_type evd ev');
+                 Array.iter (occur_rec check_types acc) args'))
   | Rel i when i > k ->
-      if not (Int.Set.mem (i-k) !cache) then
-      (match Environ.lookup_rel i env with
-       | LocalAssum _ -> ()
-       | LocalDef (_,b,_) -> cache := Int.Set.add (i-k) !cache; occur_rec acc (lift i b))
-  | Proj (p,c) -> 
-    let c = 
-      try Retyping.expand_projection env evd p c []
-      with Retyping.RetypeError _ -> 
-	(* Can happen when called from w_unify which doesn't assign evars/metas 
-	   eagerly enough *) c
-    in occur_rec acc c
+     if not (Int.Set.mem (i-k) !cache) then
+       let decl = Environ.lookup_rel i env in
+       if check_types then
+         (cache := Int.Set.add (i-k) !cache; occur_rec false acc (lift i (get_type decl)));
+       (match decl with
+        | LocalAssum _ -> ()
+        | LocalDef (_,b,_) -> cache := Int.Set.add (i-k) !cache; occur_rec false acc (lift i b))
+  | Proj (p,c) -> occur_rec true acc c
   | _ -> iter_constr_with_full_binders (fun rd (k,env) -> (succ k, push_rel rd env))
-    occur_rec acc c
+    (occur_rec check_types) acc c
   in
-  try occur_rec (0,env) c; true with Occur -> false
+  try occur_rec false (0,env) c; true with Occur -> false
 
 (***************************************)
 (* Managing chains of local definitons *)
diff --git a/proofs/pfedit.ml b/proofs/pfedit.ml
index 30b031a60..e4bae2012 100644
--- a/proofs/pfedit.ml
+++ b/proofs/pfedit.ml
@@ -215,7 +215,7 @@ let refine_by_tactic env sigma ty tac =
 (* Support for resolution of evars in tactic interpretation, including
    resolution by application of tactics *)
 
-let implicit_tactic = ref None
+let implicit_tactic = Summary.ref None ~name:"implicit-tactic"
 
 let declare_implicit_tactic tac = implicit_tactic := Some tac
 
@@ -230,8 +230,10 @@ let solve_by_implicit_tactic env sigma evk =
 	(Environ.named_context env) ->
       let tac = Proofview.tclTHEN tac (Proofview.tclEXTEND [] (Proofview.tclZERO (CErrors.UserError ("",Pp.str"Proof is not complete."))) []) in
       (try
+        let c = Evarutil.nf_evars_universes sigma evi.evar_concl in
+        if Evarutil.has_undefined_evars sigma c then raise Exit;
         let (ans, _, _) = 
-	  build_by_tactic env (Evd.evar_universe_context sigma) evi.evar_concl tac in
+	  build_by_tactic env (Evd.evar_universe_context sigma) c tac in
         ans
        with e when Logic.catchable_exception e -> raise Exit)
   | _ -> raise Exit
diff --git a/test-suite/Makefile b/test-suite/Makefile
index d779d1f9a..81321729d 100644
--- a/test-suite/Makefile
+++ b/test-suite/Makefile
@@ -360,7 +360,7 @@ modules/%.vo: modules/%.v
 # Miscellaneous tests
 #######################################################################
 
-misc: misc/deps-order.log misc/universes.log
+misc: misc/deps-order.log misc/universes.log misc/deps-checksum.log
 
 # Check that both coqdep and coqtop/coqc supports -R
 # Check that both coqdep and coqtop/coqc takes the later -R
@@ -389,6 +389,26 @@ misc/deps-order.log:
 	  rm $$tmpoutput; \
 	} > "$@"
 
+deps-checksum: misc/deps-checksum.log
+misc/deps-checksum.log:
+	@echo "TEST      misc/deps-checksum"
+	$(HIDE){ \
+	  echo $(call log_intro,deps-checksum); \
+	  rm -f misc/deps/*/*.vo; \
+	  $(bincoqc) -R misc/deps/A A misc/deps/A/A.v; \
+	  $(bincoqc) -R misc/deps/B A misc/deps/B/A.v; \
+	  $(bincoqc) -R misc/deps/B A misc/deps/B/B.v; \
+	  $(coqtop) -R misc/deps/B A -R misc/deps/A A -load-vernac-source misc/deps/checksum.v 2>&1; \
+	  if [ $$? = 0 ]; then \
+	    echo $(log_success); \
+	    echo "    misc/deps-checksum...Ok"; \
+	  else \
+	    echo $(log_failure); \
+	    echo "    misc/deps-checksum...Error!"; \
+	  fi; \
+	} > "$@"
+
+
 # Sort universes for the whole standard library
 EXPECTED_UNIVERSES := 4 # Prop is not counted
 universes: misc/universes.log
diff --git a/test-suite/bugs/closed/3825.v b/test-suite/bugs/closed/3825.v
index e594b74b6..666c64631 100644
--- a/test-suite/bugs/closed/3825.v
+++ b/test-suite/bugs/closed/3825.v
@@ -14,3 +14,11 @@ Notation qux := (nat -> nat).
 
 Fail Check qux@{i}.
 
+Axiom TruncType@{i} : nat -> Type@{i}.
+
+Notation "n -Type" := (TruncType n) (at level 1) : type_scope.
+Notation hProp := (0)-Type.
+
+Check hProp.
+Check hProp@{i}.
+
diff --git a/test-suite/bugs/closed/4375.v b/test-suite/bugs/closed/4375.v
index 03af16535..71e3a7518 100644
--- a/test-suite/bugs/closed/4375.v
+++ b/test-suite/bugs/closed/4375.v
@@ -93,14 +93,15 @@ Polymorphic CoInductive foo@{i} (T : Type@{i}) : Type@{i} :=
 | A : foo T -> foo T.
 
 Polymorphic CoFixpoint cg@{i} (t : Type@{i}) : foo@{i} t :=
-  @A@{i} t (cg@{i} t).
+  @A@{i} t (cg t).
 
 Print cg.
 
 Polymorphic CoFixpoint ca@{i} (t : Type@{i}) : foo@{i} t :=
-  @A@{i} t (@cb@{i} t)
+  @A@{i} t (cb t)
 with cb@{i} (t : Type@{i}) : foo@{i} t :=
-  @A@{i} t (@ca@{i} t).
+  @A@{i} t (ca t).
 
 Print ca.
-Print cb.
\ No newline at end of file
+Print cb.
+  
\ No newline at end of file
diff --git a/test-suite/bugs/closed/4882.v b/test-suite/bugs/closed/4882.v
new file mode 100644
index 000000000..8c26af708
--- /dev/null
+++ b/test-suite/bugs/closed/4882.v
@@ -0,0 +1,50 @@
+
+Definition Foo {T}{a : T} : T := a.
+
+Module A.
+
+  Declare Implicit Tactic eauto.
+
+  Goal forall A (x : A), A.
+  intros.
+  apply Foo. (* Check defined evars are normalized *)
+  (*  Qed. *)
+  Abort.
+
+End A.
+
+Module B.
+
+  Definition Foo {T}{a : T} : T := a.
+
+  Declare Implicit Tactic eassumption.
+
+  Goal forall A (x : A), A.
+  intros.
+  apply Foo.
+  (*  Qed. *)
+  Abort.
+
+End B.
+
+Module C.
+
+  Declare Implicit Tactic first [exact True|assumption].
+
+  Goal forall (x : True), True.
+  intros.
+  apply (@Foo _ _).
+  Qed.
+
+End C.
+
+Module D.
+
+  Declare Implicit Tactic assumption.
+
+  Goal forall A (x : A), A.
+  intros.
+  exact _.
+  Qed.
+
+End D.
diff --git a/test-suite/misc/deps/A/A.v b/test-suite/misc/deps/A/A.v
new file mode 100644
index 000000000..49aaf4a79
--- /dev/null
+++ b/test-suite/misc/deps/A/A.v
@@ -0,0 +1 @@
+Definition b := true.
diff --git a/test-suite/misc/deps/B/A.v b/test-suite/misc/deps/B/A.v
new file mode 100644
index 000000000..c01a30dca
--- /dev/null
+++ b/test-suite/misc/deps/B/A.v
@@ -0,0 +1 @@
+Definition b := false.
diff --git a/test-suite/misc/deps/B/B.v b/test-suite/misc/deps/B/B.v
new file mode 100644
index 000000000..f3cda70a9
--- /dev/null
+++ b/test-suite/misc/deps/B/B.v
@@ -0,0 +1,7 @@
+Require A.
+
+Definition c := A.b.
+Lemma foo : c = false.
+Proof.
+reflexivity.
+Qed.
diff --git a/test-suite/misc/deps/checksum.v b/test-suite/misc/deps/checksum.v
new file mode 100644
index 000000000..450045e4b
--- /dev/null
+++ b/test-suite/misc/deps/checksum.v
@@ -0,0 +1,2 @@
+Require Import A.
+Fail Require Import B.
diff --git a/test-suite/success/vm_univ_poly.v b/test-suite/success/vm_univ_poly.v
index 58fa39743..62df96c0b 100644
--- a/test-suite/success/vm_univ_poly.v
+++ b/test-suite/success/vm_univ_poly.v
@@ -38,8 +38,8 @@ Definition _4 : sumbool_copy x = x :=
 
 (* Polymorphic Inductive Types *)
 Polymorphic Inductive poption@{i} (T : Type@{i}) : Type@{i} :=
-| PSome : T -> poption@{i} T
-| PNone : poption@{i} T.
+| PSome : T -> poption T
+| PNone : poption T.
 
 Polymorphic Definition poption_default@{i} {T : Type@{i}} (p : poption@{i} T) (x : T) : T :=
   match p with
@@ -49,7 +49,7 @@ Polymorphic Definition poption_default@{i} {T : Type@{i}} (p : poption@{i} T) (x
 
 Polymorphic Inductive plist@{i} (T : Type@{i}) : Type@{i} :=
 | pnil
-| pcons : T -> plist@{i} T -> plist@{i} T.
+| pcons : T -> plist T -> plist T.
 
 Arguments pnil {_}.
 Arguments pcons {_} _ _.
@@ -59,7 +59,7 @@ Polymorphic Definition pmap@{i j}
   fix pmap (ls : plist@{i} T) : plist@{j} U :=
     match ls with
     | @pnil _ => @pnil _
-    | @pcons _ l ls => @pcons@{j} U (f l) (pmap@{i j} ls)
+    | @pcons _ l ls => @pcons@{j} U (f l) (pmap ls)
     end.
 
 Universe Ubool.
@@ -75,7 +75,7 @@ Eval vm_compute in pmap (fun x => x -> Type) (pcons tbool (pcons (plist tbool) p
 
 Polymorphic Inductive Tree@{i} (T : Type@{i}) : Type@{i} :=
 | Empty
-| Branch : plist@{i} (Tree@{i} T) -> Tree@{i} T.
+| Branch : plist@{i} (Tree T) -> Tree T.
 
 Polymorphic Definition pfold@{i u}
             {T : Type@{i}} {U : Type@{u}} (f : T -> U -> U) :=
@@ -111,7 +111,7 @@ Polymorphic Fixpoint repeat@{i} {T : Type@{i}} (n : nat@{i}) (v : T) : plist@{i}
 Polymorphic Fixpoint big_tree@{i} (n : nat@{i}) : Tree@{i} nat@{i} :=
   match n with
   | O => @Empty nat@{i}
-  | S n' => Branch@{i} nat@{i} (repeat@{i} n' (big_tree@{i} n'))
+  | S n' => Branch@{i} nat@{i} (repeat@{i} n' (big_tree n'))
   end.
 
 Eval compute in height (big_tree (S (S (S O)))).