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

Oh, and I noticed a strange behavior of EYE (which predates Jos's last 
patch):

http://ppr.cs.dal.ca:3002/n3/editor/s/LRjeoZwZ


The second test fails, meaning that the following is derived:

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

despite the fact that simpler sentences are not.

   pa

PS: I know that God works in mysterious ways, but still!
Ok, that joke is out of the way, we can discuss ;-)

On 12/07/2022 13:02, Pierre-Antoine Champin wrote:
>
> 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
>>