tuned;

--- a/src/Tools/jEdit/src/document_model.scala	Fri Mar 23 17:09:36 2018 +0100
+++ b/src/Tools/jEdit/src/document_model.scala	Fri Mar 23 20:45:46 2018 +0100
@@ -255,7 +255,7 @@
             }
             val retain = PIDE.resources.dependencies(imports).theories.toSet
 
-            for ((node_name, Some(edits)) <- purged; if !retain(node_name); edit <- edits)
+            for ((node_name, Some(edits)) <- purged if !retain(node_name); edit <- edits)
               yield edit
           }
           else Nil