src/Pure/System/isabelle_process.scala

 Isabelle process management -- always reactive due to multi-threaded I/O.
 */
 
 package isabelle
 
+import java.lang.System
 import java.util.concurrent.LinkedBlockingQueue
 import java.io.{BufferedReader, BufferedWriter, InputStreamReader, OutputStreamWriter,
   InputStream, OutputStream, BufferedOutputStream, IOException}
 
 import scala.actors.Actor