gmane.comp.ai.prolog.swi

Re: Need help

Alan Baljeu — 2008-12-01T15:29:17

Prolog is not an expert system shell. It is a general purpose programming language that happens to be very adept for doing complex search algorithms, and symbolic manipulation. Both of those features make it suitable for designing an expert system. But Prolog doesn't prescribe any method of building an expert system. Tutorials commonly advise one of two methods to build Prolog programs. One way is to make lots of facts in the Prolog database, and then build programs that query the facts and make connections. This is easy and works well for smaller prorgrams. The other is to use lists and other datastructures to manage and manipulate knowledge. This is more complicated, but is also more scalable. To learn the language, search "prolog tutorial", and choose one of the many. After, lookup the book "The Craft of Prolog" by Richard O'Keefe. Then we can talk about expert system building. Alan Baljeu ________________________________ From: menguele francois yahoo.fr> To: swi-prolog< at >iai.uni-bonn.de Sent: Monday, December 1, 2008 6:21:43 AM Subject: [SWIPL] Need help Good morning. I'm a new delphi programmer and i want to be initiate to expert system. I downloadded the delphiswi.zip which must help me to embbed prolog in delphi. The problem is that i don't know how to use it. So please can u help me. I really want to implement my first expert system. Thanks. __________________________________________________________________ Looking for the perfect gift? Give the gift of Flickr! http://www.flickr.com/gift/

Need help

menguele francois — 2008-12-01T11:21:43

Good morning. I'm a new delphi programmer and i want to be initiate to expert system. I downloadded the delphiswi.zip which must help me to embbed prolog in delphi. The problem is that i don't know how to use it. So please can u help me. I really want to implement my first expert system. Thanks.

Re: Operator definitions

Günter Kniesel — 2008-12-01T09:30:00

Richard O'Keefe schrieb: That's indeed a very nasty consequence of which I didn't think before. Thanks for the explanation. Also to Ulrich and Jan. Günter

Re: Operator definitions

Lukas Degener — 2008-12-01T08:50:35

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Richard O'Keefe schrieb: I think this is a good idea in most situations. However if you want to parse data that contains arbitrary Prolog expressions (I think this is what Günter needs), then your parser probably won't be trivial: You would have to reimplement the parsing used by SWI-Prolog, which is difficult *because* of user defined operators, etc. Here is what I would try. Not as elegant and probably not as robust as having a single parser, but -- I think -- easier to implement: 1) Use a very simple parser that only does a rough partitioning of the input (filter out comments, make string/atom-literals opaque). 2) In a second pass, put quotes around all occurrences of !!! (or whatever you are using) in the remaining regions of the input. 3) Then feed the result to SWI-Prolog. Regards, - --lu -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkkzpVQACgkQ6CpjlIRmaiCDjgCfYZ56/FNvu0F+KJ5WZajqAeTC v9EAnAmRDi/BSgP19smRqMnyFbKE6Ieg =bscn -----END PGP SIGNATURE-----

Re: Operator definitions

Ulrich Neumerkel — 2008-12-01T06:54:29

Even determining the end of a read-term would depend on the current operator definitions. If more elaborate operators are desired, UTF-8 provides plenty of characters. What about ?- op(1175, xfx, '\u2225'). in place of ||| or '\u203c' in place of !!! ?

Re: Operator definitions

Richard O'Keefe — 2008-12-01T06:23:22

On 1 Dec 2008, at 10:13 am, Günter Kniesel wrote: YIKE! There was a Prolog system that worked that way. More than one, in fact. Trying to figure out how to parse it was a nightmare, because the operator declaration that licensed a particular token might not be in the same file as the token in question. Some things just don't work well in practice. It's an even worse idea than APL's "you can't even parse me until run time" "cleverness". The problem is that some people wanted to write "a:-!." or "a:-!, b.", which means that "!" has to be in a different character class from "-". If you are happy to break that, then there would be no problem in putting "!" in the same character class as "-" and ":". Nothing stops you designing your own new syntax and plugging it in. Certainly nothing stops you writing your own parser for "data" and mapping that into some other Prolog; using operator-heavy stuff *at run time* has a nasty habit of leading to inefficiency, because what is optimised for human reading is not optimised for machine processing. (Prolog syntax itself is a good example of this.) Bill Clocksin (co-author of "Programming in Prolog" with Chris Mellish) once told me that the only major improvement to Prolog he could think of would be to abolish user-defined operators. I often think he was right.

Re: Operator definitions

Günter Kniesel — 2008-11-30T21:13:12

Ulrich Neumerkel schrieb: Hi Ulrich, I understand the historic reasons for the current state but not why it wouldn't be possible to treat !!! as a token as soon as there is a corresponding operator definition. That wouldn't require extra space in other cases (such as those you mentioned above). It might require replacing the special treatment of ! and friends in the parser to check for special tokens defined by operator declarations. I don't know how much work that is but I know it would definitely help me a lot ;) The current state prevents some very useful operator definitions. The exclamation and pipe are very intuitive in many contexts, so it is a pity that one cannot use them in operators. Günter

Re: Operator definitions

Ulrich Neumerkel — 2008-11-30T14:03:43

They are solo- and punctuation characters respectively. They do not glue together with other characters and thus will always represent one token unless quoted like '!!!'. Other characters with similar properties are ; , [ ] ( ) { } but not . which is not a punctuation character but only a symbol character to make =.. work, a remainder from the ancient ,.. notation for lists. Without solos and punctuations we would have to add extra space to a :- !. L0 = [+,a,-|L1]. resulting in less compact text a :- ! . L0 = [ + ,a, - |L1] .

Operator definitions

Günter Kniesel — 2008-11-30T12:27:48

Hi SWI team, in general, it is possible to write an operator that has another one as prefix. For instance, :- op(1175, xfx, +++). :- op(1175, xfx, ---). is OK, although + and - are operators too. This is what I would like also for ! and | but: ?- op(1175, xfx, |||). ERROR: [Thread pdt_console_client_0< at >localhost] op/3: Type error: `list' expected, found `(|)||' ?- op(1175, xfx, !!!). op(1175, xfx, !!!). ERROR: [Thread pdt_console_client_0< at >localhost] Syntax error: Operator expected ERROR: [Thread pdt_console_client_0< at >localhost] op(1175, xfx, set_stream(current_output,tty(true)),set_stream(current_input,tty(true)) ERROR: [Thread pdt_console_client_0< at >localhost] ** here ** ERROR: [Thread pdt_console_client_0< at >localhost] !) . It seems that the symbols ! and | are treated by the parser in a special way that makes it impossible to define operators that contain these symbols without being forced to add ugly quotes around the operator. Could this be fixed? Regards, Günter

RE: help about programing with prolog

Faiz ul haque Zeya — 2008-11-30T10:23:41

The program is parent(tom,socrates). parent(john,tom). succ(A,B):-parent(A,B). succ(A,B):-parent(A,C),succ(C,B). Try it with queries such as succ(john,socrates). regards Faiz ul haque Zeya From: swi-prolog-admin< at >iai.uni-bonn.de [mailto:swi-prolog-admin< at >iai.uni-bonn.de] On Behalf Of Setareh Rastad Sent: Sunday, November 30, 2008 12:33 AM To: swi-prolog< at >iai.uni-bonn.de Subject: [SWIPL] help about programing with prolog excuseme I want a simple program prolog that contains rules and fact. Thank you very much.

help about programing with prolog

Setareh Rastad — 2008-11-29T19:32:32

excuseme I want a simple program prolog that contains rules and fact. Thank you very much.

Re: delphiswi.zip

leledumbo — 2008-11-26T08:44:46

menguele francois wrote: http://gollem.science.uva.nl/twiki/pl/bin/view/Foreign/DelphiInterface This link works fine.

Re: open/4 and invalid options

Markus Triska — 2008-11-25T11:37:40

Hi Matt, To me, ignoring unknown options seems least user-friendly; silent failure is already better, and a domain error seems best. All the best, Markus

Re: depth & breadth first search

Richard O'Keefe — 2008-11-24T23:05:40

On 22 Nov 2008, at 8:46 am, Ralf Meermeier wrote: So this is a homework problem. This can *only* be a homework problem, because for serious work, iterative deepening is preferred to breadth first. Recommendation 1: GO TO YOUR LECTURER AND ASK FOR HELP. I'm a lecturer myself. One of the things that *REALLY* upsets me is students who flounder around wasting their and other people's time when they could just come and ASK me. I don't bite. Neither does your lecturer. We are PAID to explain stuff to our own students. Amongst other things, your lecturer needs to know when students are having difficulty so that s/he can revise the material appropriately. Going behind the lecturer's back is a species of deception which does nobody any good. Recommendation 2: Buy my book if you can find a copy. (The Craft of Prolog.) If you can't, buy, or at least borrow, practically ANY book about Prolog. Recommendation 3: Google for (Prolog breadth first search). What tree? If you mean the state space, you already _have_ a clause there to catch cycles, so you've done it. A little English lesson. There are distinct two words, "SEEK" and "SEARCH". Someone SEEKS something in a place. Someone SEARCHES a place for something. Someone SEARCHES FOR something in a place. You are seeking a number. You are searching a graph. Three little style lessons about Prolog. 1. Put a space after argument-separating commas. E.g., solve(STATE, PREVSTATES, []) rather than solve(STATE,PREVSTATES,[]). 2. Don't use ALLCAPS and do Separate_Words. E.g., solve(State, Prev_States, []) rather than solve(STATE,PREVSTATES,[]), and dead_end rather than deadend. (deadend looks too much like deadened.) 3. You can be brief without excessive abbreviation, and if you are worried about typing, text editors can expand abbreviations as you type. Make life easy for your reader. E.g., solve(State, Previous_States, []) rather than solve(State, Prev_States, []). _______________________________________________ SWI-Prolog mailing list SWI-Prolog< at >iai.uni-bonn.de https://mailbox.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog

[XPCE] how tu execute item actions in a popup ?

Joel Foutelet — 2008-11-24T18:18:48

Hello I'd like to use a context-menu, so I create a popup but it doesn't work : the popup is showed, but when I clik on an item, nothing happens ! Thank you for any remark . Joel Here is my code, with different tests. :- pce_begin_class(my_popup, popup, "Gestion du menu des popup "). initialise(P) :-> send(P, send_super, initialise, message := message(< at >prolog, init)), send_list(P, append, [new(_, menu_item('item 1', message := message(< at >prolog, test_item1))), new(_, menu_item('item 2', message := message(< at >prolog, test_item2)))]). /* % essai 4 creation toute simple send_list(P, append, ['item 1','item 2']). */ /* % essai 3 sans création avec new send_list(P, append, [menu_item('item 1',< at >default), menu_item('item 2',< at >default)]). */ /* % essai numero 2 avec messages par défaut send_list(P, append, [new(_, menu_item('item 1',< at >default)), new(_, menu_item('item 2',< at >default))]). */ /* % essai numero 1 avec des messages associés send_list(P, append, [new(_, menu_item('item 1', message(< at >prolog, test_item1))), new(_, menu_item('item 2',message(< at >prolog, test_item2)))]). */ % I think this is stupid ! execute(P) :-> writeln(execute), send(P, send_super, execute). % this works close(P) :-> writeln(close), send(P, send_super, close). :- pce_end_class. init :- writeln('init'). test_item1 :- writeln('item 1'). test_item2 :- writeln('item 2'). set_popup(B) :- new(P, my_popup), send(P, open, on :=B). test :- new(D, window('test')), new(B, box(100, 100)), send(D, display, B, point(10,10)), send(B, recogniser, click_gesture(right,'', single, message(< at >prolog, set_popup, B))), send(D, open).

Re: depth & breadth first search

Alan Baljeu — 2008-11-24T14:59:15

Just a hint Ralf. If you have further questions you should consult with the teacher or assistant. I won't offer more: Think of a search algorithm as generating a sequence of nodes and then selecting the matches. When you visit the first node, you find a bunch more nodes. Where do those belong in the sequence? Put them there, and then proceed to process the next "first" node. If this isn't clear yet, try running the algorithm by hand generating your sequence of nodes using DFS and BFS, and see the pattern. Write your code according to the pattern. ------------------- Hallo, In the lecture there were some remarks and restriction on how to implement the depth first search. I have been able to accomplish this assignment, but since two day I cant (I must) figure out how to convert this implementation to breadth first search! __________________________________________________________________ Looking for the perfect gift? Give the gift of Flickr! http://www.flickr.com/gift/

delphiswi.zip

menguele francois — 2008-11-24T13:25:12

please i try to download delphiswi.zip without succes. So can you send me it even by mail. Thank you!!!!!!

open/4 and invalid options

Matt Lilley — 2008-11-24T01:40:18

Hi, I've noticed that open/4 doesn't reject invalid options passed in - specifically I just spent a while trying to work out why my test program to copy files in Windows was creating files that were shorter than the ones copied in Linux. It would've been more obvious had my program not contained so many other, more subtle errors, but the thing which got me in the end was that once I realised the 0x0d bytes were being stripped out, I passed mode(binary) to open/4, and was further puzzled as to why this didn't solve the problem. (For those who are similarly surprised, the correct option is type(binary)). Adding to my confusion at this point was the documentation stated that streams opened in iso_latin_1 encoding are read 'fully-untranslated', and I suppose that's right, except that stripping out all 0x0d bytes seems to qualify as 'translation' on at least some level to me... I imagine that ignoring unknown options is useful for forward-compatibility, but perhaps we could have a system flag which would make option-list checking a bit stricter, or at least a debug flag so that a warning could be Sdprintf'd? Does anyone else have any views on this? Thanks, Matt

Re: Using the profiler to choose good command-line memory allocations?

Jan Wielemaker — 2008-11-23T20:05:47

I think so. I'd assume the difference is in the micro-second range, max milliseconds. ---- Jan _______________________________________________ SWI-Prolog mailing list SWI-Prolog< at >iai.uni-bonn.de https://mailbox.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog

Re: Using the profiler to choose good command-line memory allocations?

Jocelyn Paine — 2008-11-23T18:27:27

Hi Jan, That's interesting. I have a little program at http://www.j-paine.org/cgi-bin/spin.php that generates SF plots. Prolog source code length: trivial, fits on two pages of browser output, including plenty of white space: see http://www.j-paine.org/spin.html . For a long time, I started it using no command-line arguments. Then, a few months ago, I did a few experiments to see what memory limits it seemed happy to fit into, and added a -L128k -G128k -T128k -A128k to the command line. I have always thought after that that it started faster. Is this just my imagination? Cheers, Jocelyn _______________________________________________ SWI-Prolog mailing list SWI-Prolog< at >iai.uni-bonn.de https://mailbox.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog

Re: Using the profiler to choose good command-line memory allocations?

Jan Wielemaker — 2008-11-23T17:39:19

Hi Jocelyn, On Sunday 23 November 2008 18:21:15 Jocelyn Paine wrote: Some clarifications: * It won't start noticably (most probably not even measurably) slower when using larger stacks.All that is done with the stack limit is allocate *virtual* memory. Even using "pl -g10G" doesn't start measurably slower on my machine. * The stack limit indeed does limit how big your program may grow, which can be an important factor in annoying other users. Hmmm. Would require keeping a high watermark on the stacks. Note that the highest reached level isn't always required. The system will do a GC if the stacks have grown enough since the last check OR it gets close to the limit. This means that programs that operate close to the limit may show a significant slowdown. Still, implementing a high watermark with the resolution of a page on the stacks is fairly trivial as each page overflow calls a routine to see whether GC is appropriate. Not now, but I'll keep it in mind (or course, if someone wants to contribute it ...). Cheers --- Jan _______________________________________________ SWI-Prolog mailing list SWI-Prolog< at >iai.uni-bonn.de https://mailbox.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog