diff -r a6efad6acafd -r d887abcc7c24 src/Pure/Isar/keyword.scala
--- a/src/Pure/Isar/keyword.scala	Sun Mar 15 12:42:30 2015 +0100
+++ b/src/Pure/Isar/keyword.scala	Sun Mar 15 12:49:20 2015 +0100
@@ -39,7 +39,7 @@
   val PRF_SCRIPT = "prf_script"
 
 
-  /* categories */
+  /* command categories */
 
   val vacous = Set(DIAG, DOCUMENT_HEADING, DOCUMENT_BODY, DOCUMENT_RAW)
 
@@ -50,6 +50,9 @@
   val document_raw = Set(DOCUMENT_RAW)
   val document = Set(DOCUMENT_HEADING, DOCUMENT_BODY, DOCUMENT_RAW)
 
+  val theory_begin = Set(THY_BEGIN)
+  val theory_end = Set(THY_END)
+
   val theory = Set(THY_BEGIN, THY_END, THY_LOAD, THY_DECL, THY_DECL_BLOCK, THY_GOAL)
 
   val theory_block = Set(THY_BEGIN, THY_DECL_BLOCK)