In effect, is such construct is allowed now in 3.1M? not ( exists MyObject2(field == 'value') ) I'm just not sure what 'not' element as an 'existential operation' will do in case it's passed 'boolean' result as an operand. Would it act as a logical negation? I understand that the above construct can be simply expressed by removing 'exists' altogether, but the problem is that the above is the result of 'automatic template' generation (ie, there is a sequence of columns with 'exists' and 'not' elements and in case there is only one such element the generation might result in the above construct). Thanks, Vlad -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Edson Tirelli Sent: 20 February 2007 16:30 To: Rules Users List Subject: Re: [rules-users] logical 'not' - is there such a construct? No, the "not" conditional element is an existential operator, so the meaning is what you expressed in your first example. I thought that was what you were looking for, but apparently it is not. I never heard about any construction capable of doing what you are asking for in a rules engine... maybe someone else can throw some light in... []s Edson Olenin, Vladimir (MOH) wrote: >So, if used like that, 'not' does not have 'existential' meaning then, but >simple 'negation'? I mean, the expression > > not MyObject(field == 'value') > >would still mean 'not exists', correct? Would the expression > > not (MyObject(field == 'value')) > >mean > > MyObject(field != 'value') > >then. In other worlds, "all objects OTHER then those matching the >constraint"? > >Thanks. > >Vlad > >-----Original Message----- >From: rules-users-bounces(a)lists.jboss.org >[mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Edson Tirelli >Sent: 20 February 2007 14:37 >To: Rules Users List >Subject: Re: [rules-users] logical 'not' - is there such a construct? > > Vlad, > >In 3.1M1 you can write: > >rule X >when >not ( >MyObject( aaa == "bbb" ) and >MyObject2( bbb == "aaa" ) >) >then >// do something >end > >But remember that variables bound inside the "not" block are not avaible >in the consequence for obvious reasons. > >[]s >Edson > >Olenin, Vladimir (MOH) wrote: > > > > > >>Hi, >> >>I wonder if there is logical 'not' operator (in the meaning of "!=" -> >>'not equal') which can be applied to the whole rule? Eg: >> >>Rule x >> >>When >> >>! ( >> >>MyObject(aaa == "bbb") >> >>MyObject2(bbb == "aaa") >> >>) >> >>Then >> >>// do smth >> >>End >> >>Basically I'm looking for an operator to reverse the evaluation result >>of the expression in the brackets. The use case: in my system all >>rules are defined from 'rule passes' prospective, while the >>application should take some action in case the rule is NOT passed >>(ie, 'else' case). >> >>Any way to do that except reformulating the constraints themselves? >> >>Thanks, >> >>Vlad >> >>------------------------------------------------------------------------ >> >>_______________________________________________ >>rules-users mailing list >>rules-users(a)lists.jboss.org >>https://lists.jboss.org/mailman/listinfo/rules-users >> >> >> >> >> >> > > > >