src/Tools/jEdit/src/jedit_sessions.scala

       options.string(jedit_logic_option))
 
   def logic_ancestor: Option[String] = proper_string(Isabelle_System.getenv("JEDIT_LOGIC_ANCESTOR"))
   def logic_requirements: Boolean = Isabelle_System.getenv("JEDIT_LOGIC_REQUIREMENTS") == "true"
   def logic_focus: Boolean = Isabelle_System.getenv("JEDIT_LOGIC_FOCUS") == "true"
+  def logic_include_sessions: List[String] =
+    space_explode(':', Isabelle_System.getenv("JEDIT_INCLUDE_SESSIONS"))
 
   def logic_info(options: Options): Option[Sessions.Info] =
     try {
       Sessions.load_structure(session_options(options), dirs = session_dirs()).
         get(logic_name(options))

   /* session build process */
 
   def session_base_info(options: Options): Sessions.Base_Info =
     Sessions.base_info(options,
       dirs = JEdit_Sessions.session_dirs(),
+      include_sessions = logic_include_sessions,
       session = logic_name(options),
       session_ancestor = logic_ancestor,
       session_requirements = logic_requirements,
       session_focus = logic_focus,
       all_known = !logic_focus)