src/Pure/Thy/sessions.scala

     document_theories: List[(String, Position.T)],
     document_files: List[(Path, Path)],
     export_files: List[(Path, Int, List[String])],
     meta_digest: SHA1.Digest)
   {
-    def chapter_session: Path = Path.basic(chapter) + Path.basic(name)
-
     def deps: List[String] = parent.toList ::: imports
 
     def deps_base(session_bases: String => Base): Base =
     {
       val parent_base = session_bases(parent.getOrElse(""))

     def document_output: Option[Path] =
       options.string("document_output") match {
         case "" => None
         case s => Some(dir + Path.explode(s))
       }
+
+    def browser_info: Boolean = options.bool("browser_info")
 
     lazy val bibtex_entries: List[Text.Info[String]] =
       (for {
         (document_dir, file) <- document_files.iterator
         if Bibtex.is_bibtex(file.file_name)

 
     val input_dirs: List[Path] =
       if (system_heaps) List(system_output_dir)
       else List(user_output_dir, system_output_dir)
 
-    val browser_info: Path =
+    def presentation_dir: Path =
       if (system_heaps) Path.explode("$ISABELLE_BROWSER_INFO_SYSTEM")
       else Path.explode("$ISABELLE_BROWSER_INFO")
 
 
     /* file names */