[jboss-jira] [JBoss JIRA] (JBRULES-3626) Add support for strong negation

[Mark Proctor (JIRA)]

     [ https://issues.jboss.org/browse/JBRULES-3626?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Mark Proctor closed JBRULES-3626.
---------------------------------

    Fix Version/s: 6.0.0.Alpha1
       Resolution: Done


This was done as part of the pluggable belief system
                
> Add support for strong negation
> -------------------------------
>
>                 Key: JBRULES-3626
>                 URL: https://issues.jboss.org/browse/JBRULES-3626
>             Project: Drools
>          Issue Type: Feature Request
>      Security Level: Public(Everyone can see) 
>            Reporter: Davide Sottara
>            Assignee: Davide Sottara
>            Priority: Minor
>             Fix For: 6.0.0.Alpha1
>
>
> Drools "not" operator implements a type of "negation by failure", i.e. not X() behaves as the negation of "exists" or, in other words, translates as "it is NOT asserted that ...".
> However, another form of stronger negation is needed to express conditionals such as "it is asserted that NOT ..."
> It should be possible, then, to assert facts both in a "positive" and "negative" way, to assert THAT and THAT NOT. 
> The language should also support a "neg" CE to create "negative" patterns which will match with negative facts. I.e. it should be possible to write rules such as:
> when $p : Person() and Car( owner == $p ) then
> // a positive, matching Car is present in the WM
> when $p : Person() and neg Car( owner == $p ) then
> // a negative, matching Car is present in the WM
> when $p : Person() and not Car( owner == $p ) then
> // neither a positive nor a negative fact exists in the WM
> For a more detailed description and motivation see e.g.:
> https://oxygen.informatik.tu-cottbus.de/publications/wagner/WebRules2Neg.pdf

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira