tuned imports;

--- a/src/Tools/jEdit/src/simplifier_trace_dockable.scala	Tue Feb 18 18:43:47 2014 +0100
+++ b/src/Tools/jEdit/src/simplifier_trace_dockable.scala	Tue Feb 18 18:51:03 2014 +0100
@@ -10,7 +10,6 @@
 import isabelle._
 
 import scala.actors.Actor._
-
 import scala.swing.{Button, CheckBox, Orientation, Separator}
 import scala.swing.event.ButtonClicked
 
@@ -19,6 +18,7 @@
 
 import org.gjt.sp.jedit.View
 
+
 class Simplifier_Trace_Dockable(view: View, position: String) extends Dockable(view, position)
 {
   Swing_Thread.require()

--- a/src/Tools/jEdit/src/simplifier_trace_window.scala	Tue Feb 18 18:43:47 2014 +0100
+++ b/src/Tools/jEdit/src/simplifier_trace_window.scala	Tue Feb 18 18:51:03 2014 +0100
@@ -146,11 +146,10 @@
 
 }
 
-class Simplifier_Trace_Window(view: View, snapshot: Document.Snapshot, trace: Simplifier_Trace.Trace) extends Frame
+
+class Simplifier_Trace_Window(
+  view: View, snapshot: Document.Snapshot, trace: Simplifier_Trace.Trace) extends Frame
 {
-
-  import Simplifier_Trace_Window._
-
   Swing_Thread.require()
 
   val area = new Pretty_Text_Area(view)
@@ -162,11 +161,11 @@
 
   private val tree = trace.entries.headOption match {
     case Some(first) =>
-      val tree = new Root_Tree(first.parent)
-      walk_trace(trace.entries, Map(first.parent -> tree))
+      val tree = new Simplifier_Trace_Window.Root_Tree(first.parent)
+      Simplifier_Trace_Window.walk_trace(trace.entries, Map(first.parent -> tree))
       tree
     case None =>
-      new Root_Tree(0)
+      new Simplifier_Trace_Window.Root_Tree(0)
   }
 
   do_update(None)