cial intelligence (eg semantic networks), data base theory (eg. entity-relationship models), and office systems (eg. for representation of the virtual office). Unfortunately, the network view of data bases is usually treated informally, in contrast to the formal treatment that is available for relational data bases. The theory of information management systems attempt to remedy this situation. Formally, a network is viewed as a set of triples where f is a function symbol, x is a node, and y is a node or an attribute value. Two perspective on such networks are of interests: 1) algebraic operations on networks allow the definition of cursor-related editing operations, and of line-drawing graphics. 2) by viewing a network as an interpretation on a variety of first-order logic, one can express constraints on the data structures that are allowed there. In particular, both "pure Lisp" data structures and "impure" structures (involving shared sublists and circular structures) can be characterized. Proposition can be also used for specifying derived information as an extension of the interpretation. This leads to a novel way of treating non-monotonic reasoning. The seminar emphsizes mostly the second of these two approaches. Host: Jan Komorowski ------------------------------ Date: 21 May 1984 11:10-EDT From: DISRAEL at BBNG.ARPA Subject: Seminar - Open Systems [Forwarded from the MIT bboard by SASW@MIT-MC.] This Wednesday, at 3:00 Carl Hewitt of the MIT AI LAB will be speaking on "Open Systems". The seminar will be held in the 3rd floor large conference room. Open Systems: the Challenge for Intelligent Systems Continous growth and evolution, absence of bottlenecks, arm's-length relationships, inconsistency among knowledge bases, decentralized decision making, and the need for negotiation among system parts are interdependent and necessary properties of open systems. As our computer systems evolve and grow they are more and more taking on the characteristics of open systems. Traditional foundational assumptions in Artificial Intelligence such as the "closed world hypothesis", the "search space hypothesis", and the possibility of consistently axiomatizing the knowledge involved become less and less applicable as the evolution toward open systems continues. Thus open systems pose a considerable challenge in the development of suitable conceptual foundations for intelligent systems. ------------------------------ End of AIList Digest ******************** 24-May-84 23:20:19-PDT,16820;000000000001 Mail-From: LAWS created at 24-May-84 23:18:04 Date: Thu 24 May 1984 21:35-PDT From: AIList Moderator Kenneth Laws Reply-to: AIList@SRI-AI US-Mail: SRI Int., 333 Ravenswood Ave., Menlo Park, CA 94025 Phone: (415) 859-6467 Subject: AIList Digest V2 #63 To: AIList@SRI-AI AIList Digest Friday, 25 May 1984 Volume 2 : Issue 63 Today's Topics: Cognitive Psychology - Dreams, Philosophy - Essence & Identity & Continuity & Recognition ---------------------------------------------------------------------- Date: Mon 21 May 84 10:48:00-PDT From: NETSW.MARK@USC-ECLB.ARPA Subject: cognitive psychology / are dreams written by a committee? Apparently (?) dreams are programmed, scheduled event-sequences, not mere random association. Does anyone have a pointer to a study of dream-programming and scheduling undertaken from the stand-point of computer science? ------------------------------ Date: Mon 21 May 84 11:39:51-PDT From: Ken Laws Subject: Dreams: A Far-Out Suggestion The May issue of Dr. Dobb's Journal contained an article on "Sixth Generation Computers" by Richard Grigonis (of the Children's Television Workshop). I can't tell how serious Mr. Grigonis is about faster-than- light communication and computation in negative time; he documents the physics of these possibilities as though he were both dead serious and well informed. He also discusses the possibility of communicating with computers via brain waves, and it this material that has spurred the following bit of speculation. There seems to be growing evidence that telepathy works, at least for some people some of the time. The mechanism is not understood, but then neither are the mechanisms for memory, unconscious thought, dreams, and other cognitive phenomena. Mr. Grigonis suggests that low-frequency electromagnetic waves may be at work, and provides the following support: Low frequencies are attenuated very slowly, although their energy does spread out in space (or space/time); the attenuation of a 5 Hz signal at 10,000 kilometers is only 5%. A 5 Hz signal of 10^-6 watt per square centimeter at your cranium would generate a field of 10^-24 watt per square centimeter at the far side of the earth; this is well within the detection capabilities of current radio telescopes. Further, alpha waves of 7.8 and 14.1 cycles per second and beta waves of 20.3 cycles per second are capable of constructive interference to establish standing waves throughout the earth. Now suppose that the human brain, or a network of such brains distributed in space (and time), contained sufficient antenna circuitry to pick up "influences" from the global "thought field" in a manner similar to the decoding of synthetic aperture radar signals. Might this not explain ESP, dreams, "racial memory", unconscious insight, and other phenomena? We broadcast to the world the nature of our current concerns, others try to translate this into terms meaningful to their lives, resonances are established, and occasionally we are able to pick up answers to our original concerns. The human species as a single conscious organism! Alas, I don't believe a word of it. -- Ken Laws ------------------------------ Date: Thu, 24 May 1984 02:52 EDT From: MINSKY%MIT-OZ@MIT-MC.ARPA Subject: Essences About essences. Here is a section from a book I am finishing about The Society of Mind. THE SOUL "And we thank Thee that darkness reminds us of light." (T. S. Eliot) My friends keep asking me if a machine could have a soul? And I keep asking them if a soul can learn. I think it is important to understand this retort, in order to recognize that there may be unconscious malice in such questions. The common concept of a soul says that the essence of a human mind lies in some entirely featureless point-like spark of invisible light. I see this as a symptom of the most dire anti-self respect. That image of a nothing, cowering behind a light too bright to see, denies that there is any value or significance in struggle for accomplishment. This sentiment of human worthlessness conceals itself behind that concept of an essence of the self. Here's how it works. We all know how a superficial crust of trash can unexpectedly conceal some precious gift, like treasure buried in the dirt, or ordinary oyster hiding pearl. But minds are just the opposite. We start as ordinary embryonic animals, which then each build those complicated things called minds -- whose merit lies entirely within their own coherency. The brain-cells, raw, of which they're made are, by themselves, as valueless as separate daubs of paint. That's why that soul idea is just as upside-down as seeking beauty in the canvas after scraping off Da Vinci's smears. To seek our essence only misdirects our search for worth -- since that is found, for mind, not in some priceless, compact core, but in its subsequently vast, constructed crust. The very allegation of an essence is degrading to humanity. It cedes no merit to our aspirations to improve, but only to that absence of no substance, which was there all along, but eternally detached from all change of sense and content, divorced both from society of mind and from society of man; in short, from everything we learn. What good can come from such a thought, or lesson we can teach ourselves? Why, none at all -- except, perhaps, that it is futile to think that changes don't exist, or that we are already worse or better than we are. --- Marvin Minsky ------------------------------ Date: Wed, 23 May 84 09:49:21 EDT From: Stephen Miklos Subject: Essence of Things? It is not too difficult to come up with a practical problem in which the identity of the greek ship is important. To wit: In year One, the owner of the ship writes a last will and testament, leaving "my ship and all its fittings and appliances" to his nephew. The balance of his estate he leaves to his wife. In Year Two, he commences to refit his ship one board at a time. After a few years he has a pile of old boards which he builds into a second ship. Then he dies. A few hypotheticals: 1. Suppose both ships are in existence at the time of probate. 2. Suppose the old-board ship had been destroyed in a storm. 3. Suppose the new-board ship had been destroyed in a storm. 4. Suppose the original ship had been refitted by replacing the old boards with fiberglass 5. Suppose the original boat had not been refitted, but just taken apart and later reassembled. 6. Suppose the original ship had been taken apart and replaced board by board, but as part of a single project in which the intention was to come up with two boats. 6a. Suppose that this took a while, and that from time to time our Greek testator took the partially-reboarded boat out for a spin on the Mediterranean. In each of these cases, who gets the old-board ship? Who gets the new-board ship? It seems to me that the case for the fallaciousness of the argument for boat y (the new-board boat) seriously suffers in hypo #6 and thereby is compromised for the pure hypothetical. It should not be the case that somebody's intention makes the difference in determining the logical identity of an object, although that is the way the law would handle the problem, if it could descry an intention. Just trying to get more confused, SJM ------------------------------ Date: Wed, 23 May 84 10:47 EDT From: MJackson.Wbst@XEROX.ARPA Subject: Re: Continuity of Identity An interesting "practical" problem of the Greek Ship/Lincoln's Axe type arises in the restoration of old automobiles. Since many former manufacturers are out of business, spare parts stocks may not exist, body pieces may have been one-offs, and for other reasons, restoration often involves the manufacture of "new" parts. Obviously at some point one has a "replica" of a Bugatti Type 35 rather than a "restored" Bugatti Type 35 (and the latter is desirable enough to some people so that they would happily start from a basket full of fragments. . .). What is that point (and how many baskets of fragments can one original Bugatti yield)? In fact, old racing cars are worse. The market value of, say, a 1959 Formula 1 Cooper is significantly enhanced if it was driven by, say, Moss or Brabham, particularly if it was used to win a significant race. But what if it subsequently was crashed and rebuilt? Rebuilt from the frame up? Rebuilt *entirely* but assigned the previous chassis number by the factory (a common practice)? Under what circumstances is one justified as advertising such an object as "ex-Moss?" Mark ------------------------------ Date: 18 May 84 18:58:24-PDT (Fri) From: ihnp4!mgnetp!burl!clyde!akgua!mcnc!ncsu!uvacs!edison!jso @ Ucb-Vax Subject: Re: the Greek Ship problem Article-I.D.: edison.219 The resolution of the Greek Ship/Lincoln's Axe problem seems to be that an object retains its identity over a period of time if it has an unbroken time-line as a whole. Most of the cells in your body weren't there when you were born, and most that you had then aren't there now, but aren't you still the same person/entity, though you have far from the same characteristics? John Owens ...!uvacs!edison!jso ------------------------------ Date: Thu 24 May 84 13:00:04-PDT From: Laurence R Brothers Subject: identity over time "to cross again is not to cross". Obviously, people don't generally function with that concept in mind, or nothing would be practically identical to anything else. I forget the statistic that says how long it takes for all the atoms in your body to be replaced by new ones, but, presumably, you are still identifiable as the same person you were x years ago. How about saying that some object is "essentially identical" in context y (where context y consists of a set of properties) to another object if it is both causally linked to the first object, and is the object that fulfills the greates number of properties in y to the greatest precision. Clearly, this definition does not work all that well in some cases, but it at least has the virtue of conciseness. If two objects are "essentially identical" in the "universal context", then they may as well be named the same in common usage, at least, if not with total accuracy, since they would seem to denote what people would consider "naively" to be the same object. -Laurence ------------------------------ Date: 22 May 84 22:48:39-PDT (Tue) From: decvax!ittvax!wxlvax!rlw @ Ucb-Vax Subject: A restatement of the problem (phil/ai) Article-I.D.: wxlvax.281 It has been my experience that whenever many people misinterpret me, it is due to my unclarity (if that's a word) in making my statement. This appears to be what happened with my original posting on human perception vs computer or robotic perception. Therefore, rather than trying to reply to all the messages that appeared on the net and in my mailbox, let me try a new, longer posting that will hopefully clarify the question that I have. "Let us consider some cases of misperception... Take for example a "mild" commonplace case of misperception. Suppose that I see a certain object as having a smooth surface, and I proceed to walk toward it. As I approach it, I come to realize visually (and it is, in fact, true) that its surface is actually pitted and rough rather than smooth. A more "severe" case of misperception is the following. Suppose that, while touring through the grounds of a Hollywood movie studio, I approach what, at first, I take to be a tree. As I come near to it, I suddenly realize that what I have been approaching is, in fact, not a tree at all but a cleverly constructed stage prop. In each case I have a perceptual experience of an object at the end of which I "go back" on an earlier attribution. Of present significance is the fact that in each case, although I do "go back" on an earlier attribution, I continually *experience* it "as" one and the same. For, I would not have experienced myself now as having made a perceptual *mistake about an object* unless I experience the object now as being THE VERY SAME object I experienced earlier." [This passage is from Dr. Miller's recent book: Miller, Izchak. "Husserl: Perception and Temporal Awareness" MIT Press, c. 1984. It is quoted from page 64, by permission of the author.] So, let me re-pose my original question: As I understand it, issues of perception in AI today are taken to be issues of feature-recognition. But since no set of features (including spatial and temporal ones) can ever possibly uniquely identify an object across time, it seems to me (us) that this approach is a priori doomed to failure. Feature recognition cannot be the way to accurately simulating/reproducing human perception. Now, since I (we) are novices in this field, I want to open the question up to those more knowledgeable. Why are AI/perception people barking up the wrong tree? Or, are they? (One more note: PLEASE remember to put "For Alan" in the headers of mail messages you send me. ITT Corp is kind enough to allow me the use of my father's account, but he doesn't need to sift through all my mail.) --Alan Wexelblat (for himself and Izchak Miller) (Currently appearing at: ..decvax!ittvax!wxlvax!rlw) ------------------------------ Date: 24 May 84 18:58-PDT From: Laws@SRI-AI Subject: Continuity Other examples related to the Greek Ship difficulty: the continuity of the Olympic flame (or rights to the Olympic name), posession of the world heavyweight title if the champ retires and then "unretires", title to property as affected by changes in either the property or the owner's status, Papal succession and the right of ordained priests to ordain others, personal identity after organ transplants, ... In all the cases, the philosophical principles seem less important than having some convention for resoving disputes. Often market forces are at work: the seller may make any claim