CogentText (Shareware Version 0.2)
-----------------------------------

CogentText is a system which combines a flexible HyperText system
with the Prolog programming language. While a knowledge of
Prolog will be useful if you want to exploit the full power of the
system, it is not necessary. Simple commands will allow you
to create quite sophisticated:

* Decision trees and decision support systems
* Diagnostic systems
* Automated manuals
* Interactive tutorials and help systems

CogentText contains a built-in Prolog Interpreter which is completely
compatible with "Clocksin and Mellish" Prolog. If you learn the language
you will be able to write:

* Expert systems which can interact with the HyperText
* HyperText douments which modify themselves as a user reads
through them
* Database systems with HyperText front ends
* ???? (we leave the rest to you).


Requirements
------------

CogentText requires an IBM PC or full compatible with at least
384K of free memory.

A color monitor is recommended, as is a hard disk. Neither is mandatory
but the hard disk is definitely recommended.

If you have a hard disk then create a subdirectory and copy all the
files from the distribution diskette to it. To configure the system
(colors etc) see the on-line help system.



Starting CogentText
-------------------

The HyperText/Prolog system is contained in dct.exe and dct.xpl.
The system may be invoked with no specified document by simply typing

dct

After a few moments you will be prompted for a document name (all
CogentText documents have the suffix .ctx). To run the demonstration,
for example, type demo in response to the prompt.

To run a document directly from the command line, give the name after the
dct command e.g.:

dct demo

The file demo.bat simply invokes this command line - so just type

demo

to run the introductory document - this explains all about CogenTEXT.
The on-line Help system (available from the F1 key) described in detail
how to produce and run your own HyperDocuments on CogentTEXT.

===============================================================================

Important Note for Dos 2.1 users
--------------------------------

If you are running a DOS version prior to version 3.0 then the above
process for invoking CogentText should still work. In some rare
cases it may not. In this case, rather than typing 'dct', above,
type 'dct -e dct.xpl'. So, for example, to run the demonstration
try typing

dct -e dct.xpl demo

==============================================================================


Important Note for CogenTEXT version 0.1 users
----------------------------------------------

This version supersedes version 0.1. It contains several changes:

* A number of bugs have been fixed -

- occasional problems re-entering a document.
- problems with the use of '!' in action statements.

* A number of changes have been made

- all the options on the command menu (f2 key) now work.
Some old version 0.1 commands have been removed (they weren't
implemented anyway) and many new ones (DOS shell, File editor,
print etc..) have been added.

- A new concept has been added - the VARIABLE. The allows
you to put 'unknowns' into the text of your document. At run
time the value of these variables is computed and displayed.
The values can be names of buttons - this means that buttons
can now be made dynamic in the document. Possible uses ??

- a document which configures itself to the skill of
the user

- a forms package

==============================================================================

A word from our sponsor
-----------------------

Shareware means that you are free to make copies of this
disk and give it to your friends, relatives or whoever you think may
find it useful or fun. There are some restrictions however:

* You may not sell copies of this disk (beyond a media charge)
* This disk is for private, non-commercial use only. If you
wish to use this system in a product, please contact us
(see "HyperBase" below).

Shareware also carries with it a request :

"If you find this program to be of use then we encourage you to
send a donation to us ($35 or $50 overseas).
This gets you on our update/bug reporting list - it
also allows us to continue to develop the system."


==============================================================================

Other notes
-----------

* A number of the demonstration HyperDocuments are currently
incomplete (nothing happens when buttons are pushed).

* Users of Version 0.1 of CogentTEXT should be aware that
their .cti files are no longer compatible with this version.

There is no need to change your .CTX files UNLESS you
have used any of the parsing functions (p_xxx()) - simply
reindex them.

If you have used parsing functions then you will find
they can be replaced by the built-in sscanf() predicate -
see the help/actions/parsing pages in the help HyperDocument.

Also notice that there have been a vast number of upwardly
compatible changes made in version 0.2 (we like to think of
them as improvements!). Explore the on-line help HyperDocument.

* Users of version 1.12 of the Cogent Prolog compiler system
should replace the runtime system proexe.exe with a copy
of dct.exe from this disk (renamed proexe.exe). All your
old code should continue to work under this new runtime.


==============================================================================

******** COMING SOON **********
******* TO A COMPUTER NEAR YOU ********

*** HYPERBASE ***


We will be releasing HyperBase as a real, live, fully supported product
---------
complete with detailed documentation.

HyperBase is based on the CogentTEXT engine but supports

** GRAPHICS **

Images can be 'snapshotted' directly from the screen, stored in
compressed form on disk, have buttons added to them using the
supplied button editor and then interactively displayed from the
CogentTEXT system.

A scripting language is also supplied which will allow you to chain
images together into interactive slide shows - passing back and forth
easily between Graphics and Text modes.

-- :: --

Want to build an expert system to diagnose a car ? Point at a picture
of what is wrong, and let HyperBase invoke an expert system for
diagnosis and then display the failed component to you !!!

-- :: --

HyperBase will be shipped in September 1988 priced as follows:
--------------

Personal HyperBase - complete system, button editor, image taker,
scripting language & builtin Prolog system plus
full documentation. PRICE: $99

HyperBase developer - as above, plus: HyperBase runtime system
permitting unrestricted distribution of
HyperBase applications. PRICE: $249


Plus we continue to offer the Cogent Prolog Compiler - a full fledged
Prolog system for the PC. Full Clocksin & Mellish Prolog +++ PRICE: $200.

Programs compiled under this system can be dynamically loaded and executed
in the HyperBase system. "C" routines can also be added to the HyperBase
runtime system by using the Prolog Compiler system.

Registered users of our shareware CogentTEXT will get a discount on
HyperBase.

We will continue to offer and enhance vanilla CogentTEXT as a shareware
product.


===============================================================================


We've enjoyed hearing how people are using CogentTEXT -- please keep in
touch:


Alan Littleford
Cogent Software, Ltd
21 William J Hts
Framingham
MA 01701

(508)-875-6553 or (617)-875-6553