The  help  facility allows one to look up help pages which
       where extracted from the standard Tcl manual pages and Tcl
       scripts  during  Tcl  installation.  Help files are struc-
       tured as a multilevel tree of  subjects  and  help  pages.
       Help  files  are found by searching directories named help
       in the directories listed in the auto_path variable.   All
       of  the  files in the list of help directories form a vir-
       tual root of the help tree.  This method  allows  multiple
       applications  to  provide  help  trees  without having the
       files reside in the same directory.

       The help facility can be accessed in two ways, as interac-
       tive  commands in the Extended Tcl shell or as an interac-
       tive Tk-based program (if you have built Extended Tcl with
       Tk).

       To run the Tk-based interactive help program:

           tclhelp ?addpaths?
       Where  addpaths  are  additional  paths to search for help
       directories.  By  default,  only  the  auto_path  used  by
       tclhelp  is  search.   This  will  result  in help on Tcl,
       Extended Tcl and Tk.

       The following interactive Tcl  commands  and  options  are
       provided with the help package:

       help
              Help, without arguments, lists of all the help sub-
              jects and pages under the current help subject.

       help subject
              Displays all of help pages and lower level subjects
              (if any exist) under the subject subject.

       help subject/helppage
              Display  the  specified help page.  The help output
              is passed through a simple pager if output  exceeds
              23  lines,  pausing  waiting  for  a  return  to be
              entered.  If any other character  is  entered,  the
              output is terminated.

       helpcd ?subject?
              Change  the current subject, which is much like the
              Unix current directory.  If subject is  not  speci-
              fied,  return  to  the  top-level of the help tree.
              Help subject path names  may  also  include  ``..''
              elements.

       helppwd
              Displays the current help subject.

       help help | ?
              Displays help on the help facility at any directory
              level.

       apropos pattern
              This command locates subjects  by  searching  their
              one-line  descriptions  for  a pattern.  Apropos is
              useful when you can remember part of  the  name  or
              description  of  a  command,  and  want  to  search
              through the one-line summaries for matching  lines.
              Full  regular expressions may be specified (see the
              regexp command).

              These procedures are provided by Extended Tcl.