renamed report to report_visible;
tuned comments;

--- a/src/Pure/context_position.ML	Mon Sep 29 14:59:02 2008 +0200
+++ b/src/Pure/context_position.ML	Mon Sep 29 21:26:26 2008 +0200
@@ -2,7 +2,7 @@
     ID:         $Id$
     Author:     Makarius
 
-Context position visibility.
+Context position visibility flag.
 *)
 
 signature CONTEXT_POSITION =
@@ -10,7 +10,7 @@
   val is_visible: Proof.context -> bool
   val set_visible: bool -> Proof.context -> Proof.context
   val restore_visible: Proof.context -> Proof.context -> Proof.context
-  val report: Proof.context -> Markup.T -> Position.T -> unit
+  val report_visible: Proof.context -> Markup.T -> Position.T -> unit
 end;
 
 structure ContextPosition: CONTEXT_POSITION =
@@ -26,7 +26,7 @@
 val set_visible = Data.put;
 val restore_visible = set_visible o is_visible;
 
-fun report ctxt markup pos =
+fun report_visible ctxt markup pos =
   if is_visible ctxt then Position.report markup pos else ();
 
 end;