From: Peter F. Patel-Schneider <pfpschneider@gmail.com>

Date: Fri, 08 Mar 2013 06:29:26 -0800

Message-ID: <5139F5C6.4040200@gmail.com>

To: Antoine Zimmermann <antoine.zimmermann@emse.fr>

CC: Pat Hayes <phayes@ihmc.us>, RDF WG <public-rdf-wg@w3.org>

Date: Fri, 08 Mar 2013 06:29:26 -0800

Message-ID: <5139F5C6.4040200@gmail.com>

To: Antoine Zimmermann <antoine.zimmermann@emse.fr>

CC: Pat Hayes <phayes@ihmc.us>, RDF WG <public-rdf-wg@w3.org>

On 03/07/2013 11:02 PM, Antoine Zimmermann wrote: > Le 07/03/2013 23:25, Peter Patel-Schneider a écrit : >> I think that the current document makes the entailment not work. >> >> G1 is Ex p1(s1,x) >> G2 is Ex p2(s2,x) >> >> {G1,G2} is Ex p1(s1,x) ^ p2(s2,x) >> >> In particular, {G1,G2} is *not* Ex p1(s1,x) ^ Ex p2(s2,x) > > What? > > {G1,G2} entails G iff all interpretations that make G1 and G2 true also make > G true. Let us consider interpretation I: > > IR = {x,y,z,t} > IS = {(<s1>,x),(<s2>,y),(<p1>,z),(<p2>,t)} > IEXT(<p1>) = {(x,y)} > IEXT(<p2>) = {(y,z)} > > Let us examine the truth of G1 and G2 under this interpretation: > > "If E is an RDF graph then I(E) = true if [I+A](E) = true for some mapping A > from the set of blank nodes in the scope of E to IR, otherwise I(E)= false." > > Consider the mapping: A1 = {(b,y)} (possibly, the mapping contains other > things if there are more bnodes "in the scope", whatever this means.) > [I+A1](G1) = true > So I satisfies G1 > > Consider the mapping: A2 = {(b,z)} > [I+A2](G2) = true > So I satisfies G2 > > Now, in order to satisfy G, there must exist a mapping A such that A(b) = y > and A(b) = z. Assuming that y and z are different, the mapping cannot exist > such that [I+1](G) = true, so G is not satisfied by I. > > So, there exists an interpretation I that makes both G1 and G2 true but does > not make G true, therefore, G is not entailed. > > I am really surprised that I have to show you the proof explicitly. > > > AZ Umm, I said at the beginning of the message that the entailment does not follows. peterReceived on Friday, 8 March 2013 14:29:59 UTC

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