Syntax:  ENABLE GRAMMAR PREFIX prefix help_library

  Enables a prefix for use with a customized command language.

  This command allows you to create your own command language by
  defining a prefix that is attached to the name of a TPU procedure.

  This example enables a prefix "USER_" and associates a help library
  with it.  Note that LSE uses exactly the characters you type.  If you
  wish to use an underscore, it must be entered explicitly.

                LSE>  ENABLE GRAMMAR PREFIX user_ user_help.hlp

  As a result, if you have defined a TPU procedure named
  USER_LIST_FILES, you can execute it by typing the command

                LSE>  LIST FILES