Re: JESS: how to write If else rule
Greetings: I've been criticized by JM recently for not getting more involved in Jess solutions. So, here goes. The example below violates one of the basic principles of all rulebased systems. The logic (i.e., the Conditional Elements, CE) should ALL be in the LHS of the rules. By putting IF conditions in the RHS you have put CEs where there should be nothing but Action Elements, AE. The one thing that most folks don't realize is that a rule that states IF A or B THEN C is actually two Rules. IF A THEN C, IF B THEN C at the same time, an ELSE condition is the negation of the entire LHS of the rule. For example Rule1 IF (A and B and C and D) THEN D To enter the ELSE you would have Rule2 IF (A and B and C and D) THEN D ELSE E which is nothing more than Rule2a IF (A and B and C and D) THEN D; Rule2b IF !(A and B and C and D) THEN E; of which the else rule is Rule2b-1 IF (A or B or C or D) THEN E which is Rule2b-1a IF A THEN E Rule2b-1b IF B THEN E Rule2b-1c IF C THEN E Rule2b-1d IF D THEN E The OR statements and the ELSE statements are usually handled by the engine - sometimes called syntatical sugar. What we need to do is get back to basics and understand that rules are to solve complex problems in logic and not used to run through massive sets of numbers looking for a needle in a haystack - that's something far better handled by Java, C++, C or even ASM. Reading through the emails is like reading the old Obfuscated C programs - most of them wondering how complex to make a procedural problem and thereby justify using a rulebase? We should be using procedural languages for procedural problems, not an inference engine. Jason Morris used to have a blog called The Zen of Jess wherein he basically taught how to use a rulebase. Not sure why he quit writing except maybe he just got tired of doing the same thing day after day after day after... My suggestion is that everyone should Read The Fabulous Manual (or the Fabulous Book - JIA) BEFORE beginning to write the first rule for a practical application or asking questions online! SDG jco This above all: to thine own self be true, And it must follow, as the night the day, Thou canst not then be false to any man. Hamlet, Act 1, Scene III http://www-tech.mit.edu/Shakespeare/hamlet/hamlet.1.3.html On Dec 11, 2008, at 5:03 AM, Joao Antunes Mourao wrote: (defrule name-of-the-rule (put here your conditions for the rule, if any) = (if (condition) then (put your things here) ) (if (condition) then (put your things here) else (put your things here) )) Simple. Good luck. Joao --- unclassified email On 10-12-2008 05:47, hansari wrote: I need rule for if (condtion1) then (acton1) if else (conditon2) then (action2) if else (condition3) then (action3) else (acton4) how can perform this by using defrule please help me. thank you. Disclaimer: If you are not the intended recipient of this email, please notify the sender and delete it. Any unauthorized copying, disclosure or distribution of this email or its attachment(s) is forbidden. Thales Nederland BV will not accept liability for any damage caused by this email or its attachment(s). Thales Nederland BV is seated in Hengelo and is registered at the Chamber of Commerce under number 06061578. joao.mourao.vcf
Re: JESS: how to write If else rule
(defrule name-of-the-rule (put here your conditions for the rule, if any) = (if (condition) then (put your things here) ) (if (condition) then (put your things here) else (put your things here) )) Simple. Good luck. Joao --- unclassified email On 10-12-2008 05:47, hansari wrote: I need rule for if (condtion1) then (acton1) if else (conditon2) then (action2) if else (condition3) then (action3) else (acton4) how can perform this by using defrule please help me. thank you. Disclaimer: If you are not the intended recipient of this email, please notify the sender and delete it. Any unauthorized copying, disclosure or distribution of this email or its attachment(s) is forbidden. Thales Nederland BV will not accept liability for any damage caused by this email or its attachment(s). Thales Nederland BV is seated in Hengelo and is registered at the Chamber of Commerce under number 06061578. begin:vcard fn;quoted-printable:Jo=C3=A3o Mour=C3=A3o n;quoted-printable;quoted-printable:Mour=C3=A3o;Jo=C3=A3o org:Thales;Above Water Systems adr:;;;Hengelo;;;Netherlands email;internet:[EMAIL PROTECTED] title:THALES NETHERLANDS B.V. tel;work:2640 note:-unclassified mail- version:2.1 end:vcard
Re: JESS: how to write If else rule
Joao, I beg here to differ from this approach. This approach shows how to write if-then-else in Lisp, which is not different from writing them in any language with if-then-else conditional statements (and all of them support IF logic). Writing your conditions in a rule language like Jess assumes that you utilize benefits of rule-based approach, which includes data-driven order of execution. Dusan Sormaz Joao Antunes Mourao wrote: (defrule name-of-the-rule (put here your conditions for the rule, if any) = (if (condition) then (put your things here) ) (if (condition) then (put your things here) else (put your things here) )) Simple. Good luck. Joao --- unclassified email On 10-12-2008 05:47, hansari wrote: I need rule for if (condtion1) then (acton1) if else (conditon2) then (action2) if else (condition3) then (action3) else (acton4) how can perform this by using defrule please help me. thank you. Disclaimer: If you are not the intended recipient of this email, please notify the sender and delete it. Any unauthorized copying, disclosure or distribution of this email or its attachment(s) is forbidden. Thales Nederland BV will not accept liability for any damage caused by this email or its attachment(s). Thales Nederland BV is seated in Hengelo and is registered at the Chamber of Commerce under number 06061578. -- *** * Dusan Sormaz, PhD, Associate Professor * Ohio University * Department of Industrial and Systems Engineering * 284 Stocker Center, Athens, OH 45701-2979 * phone: (740) 593-1545 * fax:nbsp;nbsp; (740) 593-0778 * e-mail: [EMAIL PROTECTED] * url: http://www.ent.ohiou.edu/~sormaz *** To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED]
Re: JESS: how to write If else rule
Hasan, Jess (and other rule-based languages) is not procedural, but more declarative. rules are in the form: (defrule myrule (condition 1) (condition 2) (condituin 3) = (action 1) (action 2 )) Each rule is independent of others. All of them are evaluated for their conditions and one is selected to run. Conditions are in the from of patterns which are defined using facts. Order of execution of the rules is defined by set of facts. for more details read Jess manual and books or rule-based programming. Dusan Sormaz hansari wrote: I need rule for if (condtion1) then (acton1) if else (conditon2) then (action2) if else (condition3) then (action3) else (acton4) how can perform this by using defrule please help me. thank you. -- *** * Dusan Sormaz, PhD, Associate Professor * Ohio University * Department of Industrial and Systems Engineering * 284 Stocker Center, Athens, OH 45701-2979 * phone: (740) 593-1545 * fax:nbsp;nbsp; (740) 593-0778 * e-mail: [EMAIL PROTECTED] * url: http://www.ent.ohiou.edu/~sormaz *** To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED]
Re: JESS: how to write If else rule
The way one should do it in JESS is not procedurally has been expected here.
The conditions should be used to build the rules separately,
If you need an else if structure, it ideally is what JESS does naturally.
However , if your requirement is :
if(c1)
{
a1.
if(c2)
{
a2.
}
}
Then you could simply use both the conditions in the rule for firing
a2 and only c1 for a1.
hansari wrote:
I need rule for
if (condtion1)
then (acton1)
if else (conditon2)
then (action2)
if else (condition3)
then (action3)
else (acton4)
how can perform this by using defrule
please help me.
thank you.
To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]'
in the BODY of a message to [EMAIL PROTECTED], NOT to the list
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