?x => {...} rules (Re: N3 meeting - 12 pm (EDT) Monday 11 July)

Great, thanks Jos.

I just realized, however, that the example

     ?x => { :a :b :c }

could be made much more evil:

     ?x => { :god :knows ?x }.

(an inverted "simon says" example, if you like).

Dörthe, I am not sure whether we discussed this one or not...
It seems to me that this one would generate an infinite number of 
triples, namely:
     :god :knows {}.
     :god :knows { :god :knows {} }.
     :god :knows { :god :knows { :god :knows {} } }.
     # and so on...

However, contrarily to one might expect, it does not necessarily implies 
that god know everything that is true. E.g., in the current semantics,

     :a :b :c.
     ?x => { :god :knows ?x }.

does not entail, in my (possibly faulty) opinion

     :god :knows { :a :b :c }.

I am not quite comfortable with this... :-/

   pa

On 11/07/2022 22:31, Jos De Roo wrote:
> As discussed in the meeting today 
> https://docs.google.com/document/d/1A3HAUhjaVnnJ6yVbFAvIBRJQjUY9aFlQ2_bGxkD0mnE/edit#

> EYE now supports the list:setEqualTo and list:setNotEqualTo built-ins 
> and the tests below all succeed:
>
> @prefix list: <http://www.w3.org/2000/10/swap/list#>.
> @prefix : <http://example.org/test#>.
>
> #:s :p :o.
> #?x => {:a :b :c}.
>
> {(:alice :bob :charlie) list:setEqualTo (:bob :charlie :alice)} => 
> {:test1 a :OK}.
> {(:alice :bob :charlie) list:setEqualTo (:alice :bob :charlie :alice)} 
> => {:test2 a :OK}.
> {(:alice :bob :charlie ?X) list:setEqualTo (:alice ?Y :bob :charlie)} 
> => {:test3 a :OK}.
> {(:alice :bob :charlie :dan) list:setNotEqualTo (:eve :bob :charlie 
> :alice)} => {:test4 a :OK}.
> {(:alice :bob :charlie ?X) list:setNotEqualTo (:alice ?Y :bob :charlie 
> ?Z)} => {:test5 a :OK}.
>
> Re the semantics discussion, it is now also the case that the rule
>
> ?x => {:a :b :c}.
>
> always gives
>
> :a :b :c.
>
> William, it would be nice if you could install the latest EYE 
> https://github.com/josd/eye/releases/tag/v22.0711.1846

> on your http://ppr.cs.dal.ca:3002/n3/editor/ or wherever you prefer ;-)
>
> Thanks for the constructive meeting today!
>
> Kind regards,
> Jos
>
> -- https://josd.github.io

>
>
> On Fri, Jul 8, 2022 at 4:29 PM William Van Woensel 
> <william.vanwoensel@gmail.com> wrote:
>
>     Hello everyone,
>
>     The next N3-dev community meeting will take place Monday 11 July
>     at 12:00 noon EDT (check your timezone
>     <https://www.timeanddate.com/worldclock/fixedtime.html?msg=Weekly+N3+WG+Skype+meeting&iso=20220711T12&p1=43&ah=1>).
>     Barring exceptional circumstances, this is the regular time for
>     meetings.
>     Please join the Skype group
>     <https://join.skype.com/aRBuOasYurPd> if you haven’t already!
>
>     You can find the proposed agenda (discussion topics), and prior
>     meeting notes, on the Google Doc
>     <https://docs.google.com/document/d/1A3HAUhjaVnnJ6yVbFAvIBRJQjUY9aFlQ2_bGxkD0mnE/edit?usp=sharing>.
>
>
>
>     Kind regards,
>
>     William
>