jason-users Mailing List for jason

Hi Mayanne,

Sorry for the delay replying to your message.

There are various points to consider here. One thing that often happens 
in plans is to try different unifications until you get a satisfactory 
one. For example, in your example, if you had a plan

+!plan : toto(X) & X > 2 <- ... .

the interpreter would try to unify X with 0, but that wouldn't work with 
the next condition, so it would try 5 and succeed. So you'd have X 
instantiated with 5 in the plan body.

Another thing you could do in Jason is to have a plan

+!plan <- ?good_toto(X); ... .

then have another plan

+?good_toto(X) : toto(X) & X > 2.
+?good_toto(X) <-  // or do something else here to get one

Yet another thing to consider is that, in the default operation, the 
order of beliefs and rules matter, so just changing the order of those 
two rules could affect the behaviour of your program.

Not particularly relevant to your question, but also related, is the 
fact that you can customise plan selection, so if it were plans rather 
than prolog-like rules you wanted to interfere with the selection, you 
could have a Java method to have an application-specific plan selection.

Best,

Rafael


jas...@li... wrote:
> The attached message has been automatically discarded.
> 
> 
> ------------------------------------------------------------------------
> 
> Subject:
> question!
> From:
> Mayanne GUEZ <may...@th...>
> Date:
> Wed, 30 Sep 2009 18:24:17 +0200
> To:
> jas...@li...
> 
> To:
> jas...@li...
> 
> 
> Hello,
> 
> I have a question about the use of JASON.
> I would like to handle contradictory rules in JASON.
> If an agent has two rules :
> /toto(X) :- X = 0./
> and
> /toto(X) :- X = 5.
> 
> +!plan() <- ?toto(X)./
> 
> /!plan/ will return X=0.
> 
> The problem is that the second rule "/toto(X) :- X = 5" is never triggered.
> What shall I do if I also want to generate the output /X=5 / from the 
> second rule?
> 
> Thanks very much for your help.
> Best regards.
> 
> Mayane
> 

Hi all,
This message was wrongly classified as spam.
Cheers,
Rafael
PS: Mayane, you need to subscribe to the list before posting.

*******

Subject:
question!
From:
Mayanne GUEZ <may...@th...>
Date:
Wed, 30 Sep 2009 18:24:17 +0200
To:
jas...@li...

Hello,

I have a question about the use of JASON.
I would like to handle contradictory rules in JASON.
If an agent has two rules :
/toto(X) :- X = 0./
and
/toto(X) :- X = 5.

+!plan() <- ?toto(X)./

/!plan/ will return X=0.

The problem is that the second rule "/toto(X) :- X = 5" is never triggered.
What shall I do if I also want to generate the output /X=5 / from the 
second rule?

Thanks very much for your help.
Best regards.

Mayane

Dear users,

we have just released the version 1.3.1 of Jason.

This version basically fixes some bugs and adds a new demo that shows  
how to use controllers to dump the mind of the agents.

You can download it from
https://sourceforge.net/projects/jason/files/


Best regards

Jomi

Ooops, here it was, sorry, my bad.
Vin, sorry for the slow reply, we normally reply immediately to query 
like this but Jason is taking part in an agent competition that's 
currently taking place.

If I understood the problem well, I think you can solve this with a 
customised architecture for your agents (the book has a chapter on how 
to do this, and there are some examples in Jason distribution). One of 
the methods you can override there is the sendMsg, what you could do 
there is to filter the messages to "sensor" or whatever and then send 
the message using Java in the way you need.

Sorry if this has nothing to do with what you need. If I got it wrong, 
let me know and I'll dedicate more time for this but not very soon, 
probably only next week.

Best,

Rafael


Vin Baines wrote:
> Hi,
> 
> Sorry for slow reply, I've been snowed under at work.
> 
> You're right, I'm building on the work you mentioned 
> (http://www.iids.org/aigaion/indexempty.php?page=actionattachment&action=open&pub_id=261&location=thesis-Rogier.pdf-bfa451fd5967ae1e6b2d3d8f990dc368.pdf). 
> 
> 
> I'd thought it might be easier to use the existing ask performative, and 
> use this in a send message, so that agents connected to a physical 
> system in agentscape can report back data. e.g. send(sensor, ask, speed) 
> so that any sensors currently existing in agentscape will report back 
> values. Eventually I'm hoping to expand this out so that RMI type 
> actions can be called on the physical sensor, using Jason to do the 
> reasoning and then controlling sensors to improve, assert, disprove its 
> belief base of what is going on in the real world.
> 
> So, a list is maintained in agentsapce of all agents, so i can use 
> Map<AgentHandle, String> to = 
> lookupPublished(e.getToHandle().toString()) to lift the 'to' component 
> from the previous send message, which will then give me handle(s) to all 
> the sensor agents in agentscape, and pass the message on.
> 
> The problem is, I can't get this message out to agentscape. I'm hitting 
> the problem that Jason doesn't know that 'sensor' exists, and so does 
> the sensible thing, reporting that the atom isn't valid.
> 
> Is there an easy way to override this, or will it break something in the 
> jason architecture? Or a better approach?
> 
> Thanks for any suggestions!
> 
> Vin
> 
> Quoting Rafael H Bordini <r.b...@ac...>:
> 
>> Hi Vin,
>>
>> Jomi and I discussed this, and without knowing the details of the
>> interaction of Jason and AgentScape we can only try to guess some
>> possible alternatives:
>>
>> 1. Creating a new performative as you probably know is done completely
>> on the AgentSpeak side, but if we understand correctly you'll then need
>> to intercept this new performative and do something different with it
>> in the Java side. For this, what you need to do is to use a customised
>> AgArch class for your agents, and override the sendMsg method to use
>> the super-class method for normal messages and you handle the
>> askAgentScape in the way you want within your sendMsg method (with Java
>> code that gets the information from AgentScape and force the replies
>> into the agent mailbox, for example). There are some detail about
>> architecture customisation in the Jason book, and jason.sf.net/api will
>> probably help too.
>>
>> 2. If you have created a new Infrastructure which uses AgentScape to
>> create (and possibly distribute) agents (actually, I think someone in
>> the Netherlands did that, but I'm not sure), then you already have
>> methods for this and you'd need to change them to handle the new
>> performative.
>>
>> 3. Another possibility might be to use internal actions (which are
>> implemented in Java) to retrieve the info from the AgentScape side and,
>> e.g., add them in the agent's belief base or mailbox or however you
>> want the agent to have access to the results.
>>
>> Sorry if this isn't helpful, but we don't know much about AgentScape
>> and the details of how you interfaced it with Jason. Feel free to ask
>> further questions and send more details if you think we can help.
>>
>> Cheers,
>>
>> Rafael and Jomi
>>
>>
>>
>> Vin Baines wrote:
>>> Hi All,
>>>
>>> I'm using Jason agents in combination with the AgentScape platform,   
>>> where I've got a number of agents running in agentscape acting as   
>>> 'sensors'. Jason agents are being succesfully told information by 
>>>  the  agentscape agents and executing plans based upon this info,  
>>> but I want to have the ability for Jason agents to query back to  
>>> agentscape to  verify/assert. I've been thinking about the easiest  
>>> way to do this, as a bit of java code is going to be needed to deal 
>>>  with info flow  (agentscape handles & the passing of info back to  
>>> jason).
>>>
>>> The easiest (and hopefully sensible) way I can think of doing this  
>>> is  to add a new KQML performative to extend ask - e.g.  
>>> askAgentScape (for the time being - this assumes the jason agent  
>>> knows to ask agentscape rather than just ask! - but it would prove  
>>> the concept).
>>>
>>> The implementation of jason inside agentscape currently doesn't  
>>> handle any environments, so I can't just add new java code in there 
>>>  to add  this extra functionality (e.g. as per room demo).
>>>
>>> So, two questions really. Where should this be added in? I'm  
>>> thinking  extend jason with the functionality using agentscape  
>>> classes, and then use the new jason.jar into agentscape so that the 
>>>  asl files can use  something like askAgentScape(agName, value).
>>>
>>> Second question - does this sound a sensible way of going about it?   
>>> I'm keen to not go down a wrong hole for the 100th time..
>>>
>>> Thanks
>>>
>>> Vincent
>>>
>>>
>>> ------------------------------------------------------------------------------ 
>>>
>>> Crystal Reports - New Free Runtime and 30 Day Trial
>>> Check out the new simplified licensing option that enables unlimited
>>> royalty-free distribution of the report engine for externally  facing 
>>> server and web deployment.
>>> http://p.sf.net/sfu/businessobjects
>>> _______________________________________________
>>> Jason-users mailing list
>>> Jas...@li...
>>> https://lists.sourceforge.net/lists/listinfo/jason-users
> 
> 
> 

Hi,
I think this message got lost, I'm sure I approved it a few days back 
but now checking my old mail noticed it never appeared again in the 
list. Also, we're busy with the Agent Contest this week, so it may take 
a while before any of the Jason developers read it. Hopefully other 
users can help...
Cheers,
Rafael