$    define = "define/nolog"$    delete = "delete"$    mail   = "mail/noself"$    submit = "submit"$$    saved_message = f$environment("MESSAGE")$    set message/facility/severity/identification/text$$    modl__status  = %x11088000$    modl__success = modl__status + %x001$    modl__ctrly   = modl__status + %x00c$    status = modl__success$    on control_y then goto control_y$    on warning then goto error$$    check_open_file    = -       "if f$trnlnm(""modl_file"") .eqs. """" then " + ?       "signal e nofileopen ""No MODL file has been opened."""$    display            = "write sys$output"$    false              = 0$    libcall            = "@modl_system:subroutine-library"$    modlcall           = "@modl_system:modl_subroutines.com"$    read_lock          = "read/lock modl_file"$    read_lock_header   = "read/lock modl_file /key=""!HEADER!"""$    read_nolock        = "read/nolock modl_file"$    read_nolock_header = -      ...