From 2bd1dbc6fdad64f989089165a4e7367c072d2656 Mon Sep 17 00:00:00 2001
From: Claudio Sacerdoti Coen <claudio.sacerdoticoen@unibo.it>
Date: Sat, 12 Jul 2008 11:43:21 +0000
Subject: [PATCH] New feature/bug fixed (hopefully): it is now possible to use
 fixed (term) variables in fold bodies. The notation for exists is now fully
 working as expected.

---
 helm/software/components/content_pres/termContentPres.ml | 4 ++++
 helm/software/matita/core_notation.moo                   | 5 ++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/helm/software/components/content_pres/termContentPres.ml b/helm/software/components/content_pres/termContentPres.ml
index 691d4426d..a1f9268e4 100644
--- a/helm/software/components/content_pres/termContentPres.ml
+++ b/helm/software/components/content_pres/termContentPres.ml
@@ -511,6 +511,8 @@ let head_names names env =
         (match ty, v with
         | Env.ListType ty, Env.ListValue (v :: _) ->
             aux ((name, (ty, v)) :: acc) tl
+        | Env.TermType _, Env.TermValue _  ->
+            aux ((name, (ty, v)) :: acc) tl
         | _ -> assert false)
     | _ :: tl -> aux acc tl
       (* base pattern may contain only meta names, thus we trash all others *)
@@ -524,6 +526,8 @@ let tail_names names env =
         (match ty, v with
         | Env.ListType ty, Env.ListValue (_ :: vtl) ->
             aux ((name, (Env.ListType ty, Env.ListValue vtl)) :: acc) tl
+        | Env.TermType _, Env.TermValue _  ->
+            aux ((name, (ty, v)) :: acc) tl
         | _ -> assert false)
     | binding :: tl -> aux (binding :: acc) tl
     | [] -> acc
diff --git a/helm/software/matita/core_notation.moo b/helm/software/matita/core_notation.moo
index c7f1e5021..0043825ce 100644
--- a/helm/software/matita/core_notation.moo
+++ b/helm/software/matita/core_notation.moo
@@ -7,7 +7,10 @@ for @{ 'exists ${default
 (* Bugged notation: $T is not used if provided *)
 notation > "\exists list1 ident x sep , opt (: T). term 19 Px"
   with precedence 20
-  for ${fold right @{$Px} rec acc @{'exists (λ${ident x}.$acc)}}.
+  for ${ default
+          @{ ${ fold right @{$Px} rec acc @{'exists (λ${ident x}:$T.$acc)} } }
+          @{ ${ fold right @{$Px} rec acc @{'exists (λ${ident x}.$acc)} } }
+       }.
 
 notation "hvbox(\langle term 19 a, break term 19 b\rangle)" 
 with precedence 90 for @{ 'pair $a $b}.
-- 
2.39.2