src/Tools/jEdit/src/jedit/Plugin.scala

 import javax.swing.JScrollPane
 
 import scala.collection.mutable
 
 import isabelle.prover.{Prover, Command}
-import isabelle.IsabelleSystem
+import isabelle.Isabelle_System
 
 import org.gjt.sp.jedit.{jEdit, EBMessage, EBPlugin, Buffer, EditPane, ServiceManager, View}
 import org.gjt.sp.jedit.buffer.JEditBuffer
 import org.gjt.sp.jedit.textarea.JEditTextArea
 import org.gjt.sp.jedit.msg.{EditPaneUpdate, PropertiesChanged}

     def apply(name: String) = jEdit.getProperty(OPTION_PREFIX + name)
     def update(name: String, value: String) = jEdit.setProperty(OPTION_PREFIX + name, value)
   }
 
   // Isabelle system instance
-  var system: IsabelleSystem = null
+  var system: Isabelle_System = null
   def symbols = system.symbols
   lazy val completion = new Completion + symbols
 
   // settings
   def default_logic = {

     }
     case _ =>
   }
 
   override def start() {
-    Isabelle.system = new IsabelleSystem
+    Isabelle.system = new Isabelle_System
     Isabelle.plugin = this
     
     if (Isabelle.Property("font-path") != null && Isabelle.Property("font-size") != null)
       try {
         set_font(Isabelle.Property("font-path"), Isabelle.Property("font-size").toFloat)