Re: Datalog With Only Binary Relations Is Too Weak from jos.deroo.jd@belgium.agfa.com on 2001-03-19 (www-rdf-logic@w3.org from March 2001)

From: <jos.deroo.jd@belgium.agfa.com>
Date: Tue, 20 Mar 2001 00:42:24 +0100
To: drew.mcdermott@yale.edu
Cc: www-rdf-logic@w3.org
Message-Id: <OFABF3FFE5.AD96760D-ON41256A14.00816D3B@bayer-ag.com>

> [Drew]
> If we want all backward chaining we express the skolemized form as
>
> (<-- (grandparent ?a ?c)
>      (and (parent ?a ?b) (parent ?b ?c)))
>
> (<-- (parent ?a (f ?a ?c))
>      (grandparent ?a ?c))
>
> (<-- (parent (f ?a ?c) ?c)
>      (grandparent ?a ?c))

fully agreed with that
is there a difference between <-- and <= ?

> Any backward-chaining algorithm will solve this one.

I would expect so

--
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

Received on Monday, 19 March 2001 18:43:36 UTC