src/Pure/System/isabelle_process.scala

     def is_stderr = kind == Isabelle_Markup.STDERR
     def is_system = kind == Isabelle_Markup.SYSTEM
     def is_status = kind == Isabelle_Markup.STATUS
     def is_report = kind == Isabelle_Markup.REPORT
     def is_raw = kind == Isabelle_Markup.RAW
-    def is_ready = Protocol.is_ready(message)
-    def is_syslog = is_init || is_exit || is_system || is_ready || is_stderr
+    def is_syslog = is_init || is_exit || is_system || is_stderr
 
     override def toString: String =
     {
       val res =
         if (is_status || is_report) message.body.map(_.toString).mkString