src/Pure/Thy/thy_load.scala

--- a/src/Pure/Thy/thy_load.scala	Tue Jul 05 22:38:44 2011 +0200
+++ b/src/Pure/Thy/thy_load.scala	Tue Jul 05 22:39:15 2011 +0200
@@ -8,6 +8,8 @@
 
 abstract class Thy_Load
 {
+  def is_loaded(name: String): Boolean
+
   def check_thy(dir: Path, name: String): (String, Thy_Header.Header)
 }