Programmer 7500

home *** CD-ROM | disk | FTP | other *** search

/ Programmer 7500 / MAX_PROGRAMMERS.iso / CLIPPER / MISC / ESIE.ZIP / MANUAL < prev next >

Wrap

Text File | 1986-07-06 | 60.2 KB | 1,711 lines

ESIE The Expert System Inference Engine Knowledge Engineer's Manual Lightwave July 1986 P.O. Box 16858 Tampa, FL 33617 Copyright 1986 All Rights Reserved. This manual may only be distributed as one file on the ESIE distribution diskette. Such duplication and distribution is authorized without compensation as long as the diskette is a duplicate of the ESIE distribution diskette. This manual may also be distributed in printed form as long as a copy of the distribution diskette is attached. All other distribution is strictly prohibited. Page 1 Table of Contents Introduction . . . . . . . . . . . . . . . . . . . . . . 2 What is ESIE? . . . . . . . . . . . . . . . . . . . . . . 3 What is Shareware? . . . . . . . . . . . . . . . . . . . 7 ESIE Requirements . . . . . . . . . . . . . . . . . . . . 8 The ESIE Distribution Diskette . . . . . . . . . . . . . 10 Configuring ESIE For Your System . . . . . . . . . . . . 11 Starting ESIE . . . . . . . . . . . . . . . . . . . . . . 13 The ESIE Top Level . . . . . . . . . . . . . . . . . . . 14 The ESIE Rule Structure . . . . . . . . . . . . . . . . . 15 What Happens During a Consultation . . . . . . . . . . . 20 Paying For and Obtaining the Next Version of ESIE . . . . 21 Answers to Often Asked Questions . . . . . . . . . . . . 22 Enhancements Made to ESIE . . . . . . . . . . . . . . . . 25 ESIE Error Messages . . . . . . . . . . . . . . . . . . . 27 Concluding Remarks . . . . . . . . . . . . . . . . . . . 29 Page 2 Introduction ESIE (pronounced "easy") is the acronym for Expert System Inference Engine, an expert system shell otherwise known as an inference engine. With ESIE you can put some "smarts" into your personal computer. You can build custom "knowledge bases" (KBs) that can be used to aid people to do things that they would not be capable of doing, or doing as well, without the system. ESIE knowledge bases can be built to help make decisions or make our computers "more human." This manual is designed for the person who already has some experience in the field of Artificial Intelligence (AI). If this applies to you - then hi! There is a good possibility that you know at least one person on our staff. If you are brand new to the wonderful world of AI, then welcome! ESIE is a great tool for the beginner, too. The manual NOVICE was written for you. We urge you to print and read that file before getting started. The manual TUTOR guides users through the process of building a knowledge base. The knowledge base you will build is a simple one, but one that can be used to help people decide on needed equipment for their personal computer. TUTOR also provides many tips for building great and super great knowledge bases. HISTORY will give you a short history and working knowledge of AI. If you only intend on using ESIE with a knowledge base written for you, then you need only print and read the file FINAL.USE. For those whom this manual was intended, we expect that you will have done some work, or at least some reading, in knowledge based applications. We can only assume that you know something about rule structures, knowledge representation, and inferencing. If you need to bone up on this information, might we suggest that you scan over the file TUTOR? In any case, welcome to ESIE! Page 3 What Is ESIE? ESIE is the acronym for Expert System Inference Engine, and that is exactly what it is. ESIE loads in a knowledge base, and builds inferences out of the rules contained therein, to act like an Advisor. It is an Artificial Intelligence expert system shell. The normal gamut of expert systems (ES) can be built for and used by ESIE. Tools such as system configurators, medical experts, oil and gas exploration, etc, can all be done in ESIE. ESIE is a rule-based backward chaining inference engine. The acronym was also selected because ESIE is easy to use. If you are like us, then you've pulled out more than a few hairs trying to work with the complexity of most ES shells (ESS) available today. We can vividly remember thinking, "They've got to be kidding" with at least five different ESSs. Further, we are convinced that if we uncovered one more "undiscovered" bug in an ESS that we would all be permanent residents at Bellevue. ESIE is not like that. It's easy to use and easy to learn. It's a fairly simple system so that we feel good about the testing and debugging that went into ESIE. Since ESIE was written in Pascal, and not a pirated version of something hard to debug, like Prolog, it should hold you in good stead. If you were, or are, currently working for a corporation or university then you are also aware of the difficulty in getting management approval for a very expensive piece of software. ESIE is built to put some competitiveness into the ESS market. ESIE is very inexpensive and rivals many ESSs in power and it beats nearly all in speed. ESIE was originally designed to be a market test for the demand of AI software. Since it was going to be a market test, shareware was chosen as the distribution medium. Therefore, our advertising costs are nil, distribution costs are low, and demand is fairly accurately gauged. Knowledge based inference engines have a very select market at present, but that soon may change. The advent of low cost and readily available software might help the spread and acceptance of AI. However, there is a real demand for AI software. Lightwave has plans to enter the AI software market in a big way. Please keep us advised if you would like to know what we are up to. Lightwave will continue to support and enhance ESIE as long Page 4 as there are users that want to pay for it. ESIE has a long list of advantages to our users over other inference engines available on the market. One of the best advantages of ESIE is it's cost. You are well aware of how much systems can cost. Let's go through a little rundown for comparison: The best LISP processor in existence today will cost you more than $100,000.00 per person. Software and development time to build any expert system can jack the price up substantially. Now say you have targeted an area that looks pretty applicable to be "AIed." You know that when the system is complete you will want to install it in, say, fifty locations. You take six months to develop the first working model and spend $450,000.00 doing it. After you install your fifty stations you realize you have just spent $6,700,000.00. Your Vice President, in charge of new technology, unhooks his Thomson Automatic from the showcase wall and commits a most unnatural form of suicide. You would have to be working in some very high stakes game in order to recoup 6.7 million dollars through an expert system. Do you think the fifty installation points was too small? The numbers only get worse if you add more stations. The real cost to you comes in the form of specialized processors and software to run them. Many AI departments that we know of realize the problems inherent in the high stakes game of specialized processors, especially when the field is a new one to the company or the department. Therefore, many groups are turning towards existing hardware to meet their processing needs. Wisely, many are choosing micro computers because cost of installation is drastically reduced, and in many cases micros already exist at the target. This makes the cost of installation equal to development cost plus software cost. Great. So lets look at personal computer software cost. Believe it or not, there is quite a bit of AI software out there for personal computers. We have some kind of problem with all of it. Cost is still the biggest factor. Let's pick a popular price for an ESS in the marketplace: $7,500.00 per copy. (It used to be $12,000, but now is "marked down.") Now your installation costs are way down, and because the package is a little more personal and available to your researchers, you are able to complete initial development in five months and spend $350,000.00. Now you install the system in your fifty locations, and you are lucky: every one of them has a personal computer available. You step back to admire your handiwork and realize you have just spent $950,000.00. The head of your department leaves work early Page 5 and takes a long swim in the cooling tower of Unit 2 at Three Mile Island. Obviously, cost is one of the great advantages of ESIE. It is shareware. So lets say you decide to use ESIE on your target project, and that you take five months and $300,000 to build the product. Let's also assume that, for whatever reason, you decide to pay for support for all fifty+ copies of ESIE that you need. (That would certainly make our day!) After your fifty station installation you realize you have only spent $307,250. The president of your corporation hands you the highest company award, you get your picture on the cover of your company magazine and you are a labeled a hero. In addition to cost, availability is also key to your success as an AI department. You may freely make as many copies of the distribution diskette of ESIE as you like. Try that with another ESS, and, if you get past the copy protection, do it while staying out of jail. ESIE is instantly available to everyone in your group as well as everyone in your company. We personally have waited four months for a diskette to arrive - AFTER the check had been mailed from our accounting department. You can use ESIE now and forever with ease. Some of the other packages that look really good to you may be difficult or impossible to obtain. Many colleges and universities will be more than happy to discuss their latest and greatest at conventions but ask for a copy? Forget it. Also, some systems will only run on certain machines - machines you may not have and certainly do not want to buy. ESIE will run on any MS/PC DOS computer. ESIE is also easy to use and to learn. Of the knowledge bases distributed with ESIE, both DOCTOR and ANIMAL took less than eight hours apiece to build. We admit a little bias here, after all, we did build ESIE. So, it may take you ten hours, but it may only take you six. Another super advantage to paying for ESIE is the access to our AI help line. Our technical support staff will be more than happy to answer all your questions about AI, even if they are not related to ESIE. We'll even answer your questions about our competitors (fairly too!) We can point you in the right direction to find other tools from other companies to satisfy your AI needs. Of course, the staff will help you build knowledge bases to get you up and running. Oh yes, our technical support number is available twenty-four hours a day, nearly every day of the year. Paying for ESIE will also get you the upgrade to the next version, delivered to your front door. Lightwave has plans to expand ESIE by leaps and bounds, and the next upgrade will certainly be more powerful than the current version. Go for it! Page 6 We are constantly looking out for your needs. If you print and fill out the file called SUPPORT with your requests for additional features, we might well be persuaded to add them for you. We certainly want to keep improving ESIE. It is our goal to keep ESIE alive and kicking for a long long time. Last, but not least, is speed. This is one of our pet peeves concerning many ESSs today - they are just too slow. Many departments have switched to more powerful micros, such as the IBM PC AT (r), to offset slow software. Well, ESIE will run on those, too, but it doesn't have to. ESIE is fast, very fast, compared to most ESSs in existence today. Spend some time to do a benchmark of ESIE against any other system. We think you will be pleasantly surprised. All of the above are benefits to be gained from using ESIE: you drastically cut your costs (a hero maker in many a department), better availability to your software, easy to learn and use - cutting training time and costs and increasing productivity, access to the help line, the next upgrade, and much more speed. Page 7 What Is Shareware? Shareware is a software distribution concept. In shareware, it is believed: that people will pay for something they find useful, that most software costs too much, that copy protection schemes can sometimes be frustrating even to the most honest user, and that software users want to support software authors while not necessarily supporting the software middle men. Shareware is a marketing concept. The term was probably originally coined by Bob Wallace of Quicksoft, Inc. Mr. Wallace wrote PC-Write (c), a shareware full-feature text editor. We like PC-Write and prefer it as our editor-of-choice. We believe you will find PC-Write useful and to that end we will send you a copy if you support ESIE at the $145 level. ESIE is distributed under the Shareware concept. You receive the software first, from whatever source that may be, and pay only what you think the software is worth. You are free, and encouraged, to share copies of the distribution diskette with others. ESIE is marketed under the shareware concept. We prefer to think of ESIE as living software: software that continues to develop and get better, more powerful. We believe ESIE is a useful tool as it is, but can be improved. However, support for living software must come from somebody. Even software authors and AI researchers can't live on discovery and love alone. In shareware this support comes from you - the user. Most software that is distributed on the shareware principle offers additional features for your payment. ESIE is no exception. If your contribution meets or exceeds $145 you will receive: a copy of the ESIE distribution diskette for the latest and/or next version (you will receive both if the latest version is 2.0), professionally bound and printed copies of the manuals, a copy of PC-Write (c) (a very slick text editor usable with ESIE), access to the ESIE help line, and our very sincere thanks for supporting us in this effort. Page 8 ESIE Requirements In order to use ESIE you don't need much at all. For hardware you will need: an MS-DOS (r) or IBM (r) computer with at least 128 KB of RAM, and a monitor. ESIE should run on any MS-DOS (r) computer, (it has been tested on several), but we just cannot guarantee that it will run on your particular machine. ESIE will run on the IBM PC jr, PC, XT, and AT (r). The jr will require 256 KB of memory as it uses some of the available program memory for it's display. Some 128KB machines may give you the "insufficient memory" message when trying to run ESIE. Sorry guys, but you will have to pay out the extra dough for the RAM in order to run ESIE on your machine. There are all kinds of factors that can cause this to happen. ESIE will run in any machine with at least 256KB of RAM. ESIE will run in a system with either a color or monochrome monitor. Execute the program CONFIG to configure ESIE to meet your monitor needs. For software you only need DOS version 2.0 or higher, (including 3.0 and 3.1), and a word processor. Any word processor will do, but the word processor needs to be capable of producing flat ASCII files. You probably already have all the software you need. If you are not sure if your word processor produces flat ASCII files there are two tests: 1) try to build a short program with your word processor and run it through any compiler - if the compiler gets an upset stomach there is a good chance you need a different word processor, 2) take any text file you created with your editor, and at the DOS command level enter TYPE <fn>, where <fn> is the file you edited. If your file looks like a video game then you need a different editor. If it TYPEd your file as you had entered it then you are probably OK. If your editor does not produce flat files then do not panic. If you pay for a copy of ESIE at the $145 price we will send you one. The editor is called PC-Write (c) and it is a full-screen full-feature text editor. Of all the editors we have we prefer PC-Write. It just seems to "feel" the best for us. PC-Write is also a shareware product, produced by Quicksoft. Many word processors produce flat files as a matter of course. Nearly any text editor that is designed to be used by programmers, and therefore produce compilable source code, generally produce flat files. Those word processors that are designed to be used primarily by office personnel, for the creation of correspondence, sometimes do not. They use a Page 9 compression scheme, and often a coding scheme to control paging, in order to save disk and RAM space. We think it is a silly idea, but who listens to a group of AI techie types? If you are hell bent on using your current text editor, and it is one of those that do not produce flat files, then you still may be in luck. In many of these editors you have an option of producing a flat file from your edited file through a process usually labeled exportation or editing in document mode. By selecting that option through a menu you can produce a flat file that compilers, and ESIE, can read. One word of caution: make a copy of your file FIRST before attempting exportation. It seems that many companies did not bother to do much testing of this function and we have trashed many a file trying to export. Importing the file, or getting it back into editor format, is usually much worse. We wouldn't even attempt it if we were you, but good luck if you do. In whatever editor you choose, the margins and spacing can be set to whatever you choose. ESIE reads from the file in free format. That means that your file can look pretty strange if you want it to. As long as the syntax is in the correct order the file will load properly. If it does not then ESIE will report an error in the knowledge base and return you to DOS. Page 10 The ESIE Distribution Diskette The first thing you need to do is make a backup copy of the ESIE distribution diskette. This will protect you in case your working diskette gets damaged and will allow you to configure ESIE for your own personal use. If you like ESIE, then making the copy first makes it easier for you to pass it along to your friends and associates. You can make a backup copy of ESIE using either the DOS COPY or DISKCOPY command. The definition of the distribution diskette is a diskette that is an exact duplicate of the diskette as it is shipped from Lightwave. You can test the accuracy of your diskette by entering the command: CHECK *.* at the DOS prompt. The output from the CHECK program must exactly match the information in the file CHECK.TXT, excluding the CRC for CHECK.TXT and the total. The above test will also tell you if you have a damaged disk. The CHECK program is distributed with all of Lightwave's products, and it calculates the CRC of the named file(s). The reason the CRC for the file CHECK.TXT will not be correct is because the CRC for the file must be added to it, which will change the CRC. The total will be incorrect for the same reason. Everything you need except hardware, DOS and an editor, is on the ESIE distribution diskette. Page 11 Configuring ESIE For Your System Before you can execute the ESIE program, you must configure ESIE for your system. (If you try to run ESIE before completing the configuration it will tell you that the file ESIE.CFG was not found.) ESIE can be configured to run on either a monochrome or color monitor. If you have a color monitor, you can select the colors you want. ESIE can use any of the sixteen colors defined for color-graphics systems. These colors are: black darkgray blue lightblue green lightgreen cyan lightcyan red lightred magenta lightmagenta brown yellow lightgray white To execute the configuration program, type in CONFIG at the DOS prompt. CONFIG will then create the file ESIE.CFG and ask you if you have a color monitor. If you have a monochrome monitor, then CONFIG will finish building the ESIE.CFG file and return you to DOS. If you have a color monitor, then CONFIG will ask you six more questions. The answer to each of these questions requires that you give CONFIG one of the valid colors above. The six questions asked for color system users are: What color would you like the background? What color would you like question text? Color for answer (user response) text? Color for top level? Color for the result and trace? Finally, color for error messages? After you have given a valid color for each question, then CONFIG will return you to DOS. If you have a color monitor, then we recommend these colors to get you started: For background: blue. For question: lightgray. For answers (user responses): lightmagenta. For toplevel: yellow. For result and trace: lightcyan. Page 12 For error: lightred. If you do not like the colors you have chosen the first time around, or you change the type of monitor that ESIE is running under, then you may re-execute CONFIG at any time. Page 13 Starting ESIE Getting ESIE fired up will probably be one of the easiest things you do today. The only three files you need in the computer to use ESIE are the ESIE.COM file, the ESIE.CFG file and the file where the KB is. The ESIE.CFG file is created when you execute the CONFIG program. For purposes of example, it will be assumed that you are using the ANIMAL KB provided with the distribution diskette. When you start to build your own KBs, simply substitute that file for ANIMAL. ESIE will run in any drive and directory, including hard disks, as long as the needed files are present. Then, type in ESIE at the DOS prompt. The ESIE introductory screen will appear. It contains copyright information and some benefits you will receive if you pay for your copy of ESIE. At the top of the introductory screen is a prompt asking you to supply the file name where the knowledge base may be found. You may enter any name you please. Type in ANIMAL for this example. If the file exists, then ESIE will attempt to load that file. If no loading errors are found, then ESIE will take you to the top level. If there are errors in loading the KB, then ESIE will list where it found the errors and return you to DOS. If the file does not exist, then you have the option of trying again. Just hitting the 'Y' or the 'N' key will answer this prompt. ESIE loads files faster than most, if not all, other ESSs, but be patient if you are loading a very large KB, especially from floppy diskette. Then, after ESIE tells you the load is complete, type in GO. The consultation will now begin. To leave ESIE type in EXIT at the top level. Page 14 The ESIE Top Level You will know when you have reached the top level by the distinctive ESIE prompt. It looks like this: "==>". At the top level you have four different command options: TRACE ON, TRACE OFF, GO, and EXIT. While you can have as many leading and trailing blanks as you wish, ESIE is not quite free form on the command line. You must have one and only one space between the TRACE and YES/NO options. Other than that, ESIE is free form. Importantly, ESIE is case insensitive. Capitals look just the same as minors to ESIE. This is also true in the KB and in end user responses. ESIE is case insensitive everywhere. We like this feature. We hate building rules to take care of the same idea but duplicated everywhere to take care of case, and the idea that a variable means something different because the first letter is capitalized drives us up the wall. When you first enter the top level, trace is off by default. You can turn trace on using the TRACE ON command. Use trace when you are building your own KB and want to follow execution in order to debug the KB. Turning trace on will tell the system to constantly keep you informed of what it is currently looking for and what information it has learned. You can turn the trace back off again by entering the TRACE OFF command. The GO command is the command to tell ESIE to begin a consultation with the KB that was loaded. ESIE will continue with this consultation until it is complete or until an error is found in the logic of the KB. You may not turn trace on or off once a consultation has begun. If the user types in TRACE ON, TRACE OFF, GO or EXIT in response to a question, then ESIE will treat that as the response to the question. Once ESIE has completed the consultation, or found an error in the logic of the KB, it will return you to the top level for additional commands. Use the EXIT command in order to leave ESIE and return to DOS. After a consultation is complete, you have the option of entering ANY of the four commands, including GO, again. Page 15 The ESIE Rule Structure There are seven types of rules in ESIE. That's all. Two of the rule types must be included once and only once, three may be included once or not at all, and the other two may be included from zero up to the maximum number of times, which, as you will see, is quite large. If you are familiar with IBM (r) manuals, then you will probably be able to read the following; then again, those never were my favorite manuals. Below is the syntax for the seven types of rules in ESIE: [introtext is <text>] [legalanswers is/are [<variable>]... *] goal is <variable> [<ifrule> [<andrule>]... <thenrule>]... [question <variable> is/are <text>]... answer is/are <text> <variable> [termtext is <text>] Where: <ifrule> is defined as: if <variable> is/are <value> OR if <variable> </=/> <number> and <andrule> is defined as: and <variable> is/are <value> OR and <variable> </=/> <number> and Page 16 <thenrule> is defined as: then <variable> is/are/= <value>/<number> and <variable> is defined as any string of ascii characters excluding the space, double quote and end-of-line up to 100 characters long. and <value> is defined as any string of ascii characters excluding the space, double quote and end-of-line up to 100 characters long. and <number> is defined as any integer in the range -32768 through 32767. and <text> is defined as: "[<any character>]..." Again, capital letters and minors are treated exactly alike as far as ESIE is concerned. In the syntax above the '/' means "either or." The symbol "..." means "repeat as often as desired." The brackets mean that the item is optional. You will note that LEGALANSWERS, IF, and QUESTION type rules may not even be included in the KB, although a KB without rules isn't going to be of much use. The <text> parts of the above rule types may be any character at all except for the quotation mark. The quotation mark terminates <text>. Spaces are allowed in <text>, but double quotation marks, to indicate a single, are not. The length of <text> is unlimited and may include end-of-line characters, page feeds, or whatever you wish to improve the appearance of your output. Let us list some specifics, first, then we will go into what each rule does. First, blanks, end-of-line markers, double quotes, and end-of-file markers are the only recognized delimiters in ESIE. There must be at least one delimiter between any two Page 17 tokens in the KB. All the following are valid <variables> and <values>: 1234567890()*&^%$#@!+_=[]{} .......................... wow!.i.can.type.in.anything WOW!.I.can.TYPE.in.ANYTHING The last two of the above are identical as far as ESIE is concerned. Although special characters are valid in <variables> and <values>, and may even lead such items, it would be a good idea to stay away from the mathematical symbols. ESIE's capability to do more math in the future might make some of your variables become mathematical equations. In this regard, especially look out for the minus sign - it habitually gets used in multi-word <variables>. A better alternative would be to use the period. The GOAL and ANSWER rules types must be included, and must be in the KB only once. If the LEGALANSWERS rule type is included, it can only be included once. There is absolutely no requirement that rules be placed in the KB in any order. In a fully-structured KB, in fact, the order of the rules is totally inconsequential, any rule or any rule type may come before or after any other rule or rule type. In some KBs the logical structure is not complete, so it may be wise to place some rules before others. Now for some information on what these rules do: The LEGALANSWERS rule is used to constrict what the end user of your KB can use as responses. This is very useful to keep the end user on track, and to correct him in case of typos or misunderstandings. Using LEGALANSWERS can make testing your KB much easier and more complete. If LEGALANSWERS is omitted, then anything the end user types in is a valid response. The splat, (*), is used to terminate the LEGALANSWERS rule. Although the splat, by itself, is a totally valid <variable> or <value> we didn't think many of you would want that as a valid response, so we used it as a terminator. The GOAL rule specifies what you are looking for, that is, it determines what this consultation and KB are all about. The IF rules are the real meat of any KB. Here's how they work: the <variable> right after the IF is evaluated and Page 18 compared with the <value> after the IS/ARE/</=/>. If the value of the variable compares favorably with the <value> then there is a match and ESIE drives on. AND parts are compared the same way. Comparison stops on any rule were an IF part or an AND part do not compare favorably. However, if they all compare favorably, then the rule succeeds and the <variable> immediately after the THEN is set to the last <value> specified in the rule. For example: if age > 17 and status is alive then type.person is living.adult Let's assume that age has already been set to 34, that status has been set to 'alive', and GOAL is TYPE.PERSON. ESIE begins looking through the KB, starting at the top, for IF rules that could satisfy the type.person goal. When it finds the above rule it determines that yes, age is > 18 and status is alive, so the rule succeeds and type.person is set to living.adult. At this point evaluation stops and ESIE makes its report and returns you to the top level. The QUESTION rules are evoked by ESIE when it has gone through the entire KB and can find no IF rule that satisfies what it is currently looking for. It then checks to see if it has a question that it can ask the end user so that it may determine what a <variable> should be. The <text> part of the question is displayed and whatever the end user types in is what <variable> is set to, if the response is legal. If LEGALANSWERS has been specified, then the response is checked to see if it is one of legal ones. If it is not a legal response, then ESIE will list the possible responses, and ask the question again. This will continue until the end user has selected one of the legal answers. If it is legal, then the <variable> specified in the QUESTION rule will be set to the response. If LEGALANSWERS has not been specified, then whatever the user types in is legal. The ANSWER rule is used only when ESIE is done. After ESIE has found the <variable> in the goal statement he will display the <text> in the answer statement followed by the value evaluated from the <variable> in the ANSWER rule. You will note that you do not have to display the same <variable> as in the GOAL statement, but that you will often want to. Getting tired reading yet? Oh well, just two more: The INTROTEXT rule is used to define text that you want displayed before a session begins. The introductory text can be as long as you want it to be. ESIE will stop every 22 lines to let the user read what is on the screen. TERMTEXT is used to define text that you want displayed after Page 19 a session is complete. As with INTROTEXT, the text can be as long as you want it to be. ESIE will stop every 22 lines to let the user read what is on the screen. Now for some limits. Just how much of all this good stuff can you enter in a knowledge base? Lots: Up to 1000 IF rule lines. Up to 300 QUESTIONs. Up to 50 <variables> for LEGALANSWERS. Up to 12000 bytes of text. Up to 400 different symbols. 1 & only 1 GOAL. 1 & only 1 ANSWER. In addition, ESIE will look for up to 50 different rules to satisfy at a time and can learn up to 200 facts before running out of memory space. If these parameters do not meet your needs for KB construction, then please let us know. Page 20 What Happens During A Consultation After ESIE has loaded the KB into internal structures, and the GO command has been issued, ESIE then pushes the GOAL onto a stack. The stack contains items to be searched for, currently looking for the one at the top of the stack. Then ESIE looks through the IF rules for a conclusion that matches the current stack. When one is found then ESIE looks through the comparators, one at a time, until one is found to not compare to its value, or they are all found to compare favorably. If it does not compare favorably then the variable is pushed onto the stack. ESIE continues in this fashion. When ESIE can not find an IF rule in the KB with a conclusion identical to what is on the stack then ESIE turns to the QUESTIONs and LEGALANSWERS to get information from the end user. Any legal response is what the <variable> is set to. Often ESIE does not need to push anything on the stack as all the IF and AND parts of rule compare favorably. In this case the rule succeeds and the conclusion <variable> is set to the <value>. In this way ESIE continues to get information and pop search items off the stack until it learns what the GOAL variable is, or until ESIE has searched the entire KB and found nothing. In the latter case ESIE reports an error in the knowledge base and returns you to the top level. In the former, ESIE reports the ANSWER <text> and <variable> and returns you to the top level. Page 21 Paying For and Obtaining the Next Version of ESIE Now comes the part we all hate to discuss. What is ESIE going to cost? Well, that is totally up to you. We happen to believe that most people are honest and will pay for something they find useful. We also believe that most software costs too much, and that most AI software costs much too much. We dislike copy protection schemes and there are none in ESIE. And we believe that you will want to see ESIE grow and be supported. If your contribution meets or exceeds $145 you will receive: a copy of the ESIE distribution diskette for the latest and/or next version (you will receive both if the latest version is 2.0), professionally bound and printed copies of the manuals, a copy of PC-Write (C) (a very slick text editor usable with ESIE), access to the ESIE help line, and our very sincere thanks for supporting us in this effort. We think of ESIE as living software: software that continues to develop and get better, more powerful. We believe ESIE is a useful tool as it is, but can be improved. However, support for living software must come from somebody. Even us software authors and AI researchers can't live on discovery and love alone. In shareware this support comes from you - the user. If you happen to be working for a company and are considering ESIE as your ESS of choice, then we have two additional options available to you. First, you may order ESIE using a valid purchase order. Second, if you want more than one person to get complete support for ESIE, including access to our technical help line, we have volume discounts. If you like the ESIE product, and would like to incorporate ESIE into an existing or future product, then Lightwave may license the source code to you. Such licenses require written contracts and trust funds. Mail for ESIE may be sent to: Lightwave P.O. Box 16858 Tampa, FL 33617 Page 22 Answers to Often Asked Questions How do you pronounce ESIE? ESIE is pronounced exactly as you would pronounce the word "easy." What is an Inference Engine? An inference engine is a computer system that mimics the process of human thought. It attempts to distill the human reasoning process into a computer program. What would I use ESIE for? ESIE can be used in any place a human expert would be used. The best places for the use of ESIE are in situations where the experts in that field are hard to come by or are too expensive to hire. This does not mean that ESIE should be used only on say, space missions, but any place where there is not enough qualified people to do the job. Using ESIE, it is possible to provide enough support to a non-expert to enable him or her to complete the task effectively. I'm new to this AI stuff, where should I start? Start with ESIE. ESIE is an excellent tool for the newcomer in AI. Manuals included with ESIE give you an idea of what AI is all about, and guides you through the process of building your own knowledge base. After that, the experts at Lightwave can help you build real systems that can prove beneficial to you and your company. Someone I know wants to use ESIE, can I give him a copy? Absolutely. ESIE, although copyrighted, may be copied and shared. The only requirement is that the copy you give him is a duplicate of the distribution diskette. What enhancements are planned for the next version? Our list of possible enhancements to ESIE is quite large, and we are eager to put them all into play. Which ones we implement first will depend on input from our user community. I want my question text to span several lines on the screen. Page 23 How do I do that? Nothing special is required. ESIE currently supports text with any character used except for the double quote. Therefore, your text can span as many lines as you want it to. I know absolutely nothing about computers. Can I use ESIE? Yes. A majority of ESIE users are also first time computer users. Many report having little or no problems in turning themselves into successful knowledge engineers. Who are some of Lightwave's paying customers for ESIE? AT&T, Bell Labs, the U.S Navy, the U.S. Department of Agriculture, the Italian National Assembly, NASA, the European Space Agency, and Control Data can all be counted among our satisfied customers. What is Lightwave's phone number? As Lightwave is a growing company we are subject to move at any time. As we have no control over who is using our software in the field, we cannot give every user our new phone number. Therefore, we have not included our phone number in the manuals or programs. For this same reason we use a post office box as our mailing address. Requests to our mailing address will net you our current phone number. Is Lightwave a real business? Yes. Our company name changed recently from Lightwave Consultants to Lightwave. The name change reflects our changing direction from consulting to software. Lightwave's primary customers still are firms that request contract programmers in the Tampa Bay area of Florida. As these contracts expire, and sales in software gain strength, Lightwave will turn into a major software house. ESIE is a great product, but I'm looking for something a little different. I need a tool to manipulate and analyze text or datum for logical or mathematical context. Where do I turn? The best place to turn for this type of Artificial Intelligence tool is: Mike Pincus Thunderstone Corporation P.O. Box 839 Page 24 Chesterland, OH 44026 Thunderstone makes several tools that work in this area of AI. The tools are excellent and the price is right. What exactly is a rule line? A rule line is an IF <variable> <value> pair. For example: if age < 10 then type.person is child has two rule lines, while: if age > 18 and status is alive then type.person is living.adult has three. Page 25 Enhancements Made to ESIE Below is a list of enhancements made to ESIE version 1.1 that make up version 2.0. Added speed. Several algorithms are changed to increase ESIE's speed. A bug was fixed: in version 1.1, if the item on top of the stack could not be satisfied, then everything was popped off the stack except the goal and ESIE would continue from there. In 2.0, only the top element of the stack is popped off and execution then continues from that point. This fix repairs the problem of an answer being in the knowledge base but never being found. Oddly, this problem was never reported from the field. It appears as though users are designing knowledge bases where this capability is not required. Drawbacks: this fix significantly slows down ESIE, negating the increased speed gained from other changes. If users request that this fix be removed, it may be removed for version 3.0. The places in the KB where <text> is specified may now have unlimited quantities of said text. The maximum that may be specified in any KB is now 12,000 total bytes or characters. Version 2.0 allows users to type ahead. Users can now enter responses to ESIE prompts before ESIE is ready to accept them. This type ahead includes the prompt for KB file name. Drawbacks: this change disables the DOS ctrl-prtsc option that copies screen output to the attached printer. Better KB read algorithms are incorporated for 2.0. More error detection is done on the KB before run time. The KB is also read in faster, but the storing of tokens in ESIE internal format negates the increase in speed. 2.0 of ESIE adds the capability for limited numerical comparisons in the KB. Both the IF and the AND parts of rules may specify a math operator instead of the standard IS/ARE. The valid math operators are: '<', '>', and '='. If a math operator is specified, then the token following the operator must be an integer in the range -32768 to 32767. ESIE functions on these operators instead of direct equivalence comparisons. ESIE may now be configured for different type monitors. If a color monitor is attached, then the 16 different colors may be selected for each of: background, question text, user response text, toplevel text, result and trace text, and Page 26 error text. Version 2.0 of ESIE greatly expands the limits imposed on 1.1 users. Rules lines are now at 1000, questions at 300, cache at 200, stack stays at 50, and legalanswers stay at 50. A new, internal data format, the symbol table, is restricted to 400 different tokens. This means that 400 different variables and values can be specified in the KB and in user responses. If a legalanswers statement was included, then user responses will always match those tokens. Added the capability for introductory text to explain the KB. Added the capability for terminating text, to explain the conclusion more fully. Page 27 ESIE Error Messages Below is the list of error messages you might encounter while operating ESIE. As the error messages are straightforward, no suggested corrective action is given. Configuration file not found. Please execute the program CONFIG before continuing. File ,<filename>, does not exist. Do you wish to try again? (Y/N) Symbol table space exhausted. Please reduce number of vars/values. Text string found where variable/value expected. Too much question/answer text in Knowledge Base. Please reduce. There are too many rules in the Knowledge Base. There are too many questions in the Knowledge Base. Too many legalanswers encountered in the LEGALANSWERS rule. Number does not follow mathematical rule in Knowledge Base. Token is: <token> Goal encountered more than once in Knowledge Base. Answer statement encountered more than once in Knowledge Base. LEGALANSWERS has been specified more than once in the knowledge base. INTROTEXT has been specified more than once in the knowledge base. TERMTEXT has been specified more than once in the knowledge base. Invalid rule found in Knowledge Base. Invalid rule begins with: <token> Goal statement not found in the Knowledge Base. Answer statement not found in the Knowledge Base. Stack limit exceeded (search space exhausted). Page 28 Cache space exhausted. No room for learned information. I'm sorry, but <answer> is not acceptable. Please choose your answer from one of these: Error in Knowledge Base. <goal> searched for but not found. Page 29 Concluding Remarks We at Lightwave think ESIE is a great program. However, this program is only going to get better through your input, both in the form of suggestions for improving this product and in financial support. We wish to thank all of those who have given us positive input in the past. We hope that we are satisfying some need for our users and that we are encouraging the learning and spread of Artificial Intelligence.