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Re: Entailment versus implication

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Wed, 13 Feb 2002 16:26:09 -0500
Message-Id: <p05101413b89089e0ebf9@[192.168.0.6]>
To: Patrick Stickler <patrick.stickler@nokia.com>
Cc: w3c-rdfcore-wg@w3.org
>On 2002-02-11 17:35, "ext Pat Hayes" <phayes@ai.uwf.edu> wrote:
>
>
>>>  So, when folks say that
>>>
>>>  _:B ex:father #Bob .
>>>  _:B ex:gender ex:Male .
>>>  _:G ex:father #Bob .
>>>  _:G ex:gender ex:Female .
>>>
>>>  entails
>>>
>>>  _:B ex:gender ex:Female .
>>>  _:G ex:gender ex:Male .
>>>
>>>  I start to wonder if we are all talking about the same thing.
>>>
>>>  Certainly the first set of triples do *not* imply the latter
>>>  pair of triples. How could they?
>>
>>  Well, it goes outside RDF, but one could argue that if it is known
>>  that ex:father is functional, ie people only have one father, then
>>
>>  _:B ex:father #Bob .
>>  _:G ex:father #Bob .
>>
>>  together entail _:G = :_B,
>
>OK, here's where you lost me. How does the fact that _:G
>and _:B both have the same father, even if it were known that
>ex:father were functional, imply that _:G and _:B are
>the same resource?

Oh, I see. I read that as _:B and _:G were both Bob's father, not the 
other way round. I think we agree on the logic now, yes?

Pat

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Received on Wednesday, 13 February 2002 16:26:13 EST

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