11/18/77  - Dictionary information

Dictionaries are used to perform the word processing tasks of hyphenation and
spelling error detection. A brief description of these applications and related
information is provided below.


Hyphenation: The runoff and compose commands, both used to format text, can
optionally perform hyphenation. Each word requiring hyphenation is looked up in
a sequence of dictionaries defined by the "dict" search list.
The dictionaries are searched in order and the word is hyphenated as specified
in the first dictionary in which the word is found. If the word cannot be found
in any of the dictionaries, then it is not hyphenated.


Spelling error detection: The technique used for spelling error detection
consists of the following three steps:
  1. Use the create_wordlist command to make an alphabetized list of all unique
words contained in a document. This list is called a "wordlist".
  2. Use the trim_wordlist command to remove from the wordlist all correctly
spelled words, i.e., all words that can be found in a set of dictionaries.
This operation is called "trimming".
  3. Use the print_wordlist command to print the remaining words in the
wordlist. Check these words for spelling errors.
  The words printed in step 3 are those words contained in a document that
could not be found in a dictionary. These words are likely to be misspelled.
Normally, the number of words that will need to be checked is exceedingly small
when compared to the original document.
  The dictionary search used by the trimming operation in step 2 is the same
type of search used for hyphenation. By default, the "dict" search list is
used. However, the trim_wordlist command allows the user to specify the
dictionaries explicitly.


Spelling error correction: When misspelled words are detected as described
above, they can be easily corrected by use of the revise_words command.
This command revises all instances of one or more misspellings within a
document. Because it deals specifically with words, it can easily make
revisions that are difficult or tedious to perform with an ordinary text
editor.
  For many spelling errors, the proper correction can be determined merely by
examining the misspelling. In some cases, however, it is necessary to examine
the context of the misspelled word before making a correction.
The locate_words command is provided for this purpose. It can locate and print
in context all instances of a given word (misspelling) within a document.


Standard dictionary: A standard dictionary is provided for use in hyphenation
and spelling error detection. At present, a preliminary version of the standard
dictionary is available. This version is not complete. It contains
approximately 29,000 words. Hyphenation points are specified for most, but not
all, hyphenatable words. An expanded version of the standard dictionary will be
made available in the future.
  The pathname of the standard dictionary is >unb>standard.dict.
By default, the dict search list contains only this pathname.


User dictionaries: Commands are provided that enable users to create, modify,
and examine dictionaries. These commands include add_dict_words,
count_dict_words, delete_dict_words, and list_dict_words. Another command,
find_dict_words, can be used to find words in the dictionaries defined by the
"dict" search list. This enables the user to easily determine what effect
hyphenation or trimming will have for any given word.
  User dictionaries can be added to the "dict" search list to augment or
replace the standard dictionary. Normally, user dictionaries should precede the
standard dictionary in the search list. This allows a user to specify a
different hyphenation for a word. Also, it allows a user to specify the
"no-trim" attribute for a word.
  The no-trim attribute can be specified at the time a word is added to a
dictionary and indicates that the associated word should not be trimmed by the
trim_wordlist command. This prevents a word from being trimmed even though it
may appear in a subsequent dictionary in the search list. This feature is of
use when a standard dictionary word has some special significance in a
particular document. In this case, a user may want to see the word in a
wordlist rather than have it trimmed.


Summary of commands: The commands mentioned above are listed below in groups
according to function. Separate help files exist for each of the commands.


Hyphenation:
    compose
    runoff


Spelling error detection:
    create_wordlist
    print_wordlist
    trim_wordlist


Spelling error correction:
    locate_words
    revise_words


Dictionary maintenance:
    add_dict_words
    count_dict_words
    delete_dict_words
    find_dict_words
    list_dict_words


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Historical Background

This edition of the Multics software materials and documentation is provided and donated
to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. 
as a contribution to computer science knowledge.  
This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology,
Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL
and BULL HN Information Systems Inc. to the development of this operating system. 
Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970),
renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership
of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture 
for managing computer hardware properly and for executing programs. Many subsequent operating systems 
incorporated Multics principles.
Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., 
as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. .

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Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without
fee is hereby granted,provided that the below copyright notice and historical background appear in all copies
and that both the copyright notice and historical background and this permission notice appear in supporting
documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining
to distribution of the programs without specific prior written permission.
    Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc.
    Copyright 2006 by BULL HN Information Systems Inc.
    Copyright 2006 by Bull SAS
    All Rights Reserved