Re: [DIG-users] Strange Inference Behaviour

[LECUE F. RD-TECH-R. <fre...@or...>]

Kris and all,
=20
  I understand your explanation. However in case I suppose a EL+ DL and =
the following Knowledge Base (I update "All" by "Some"):
<impliesc>=20
<catom name=3D"Boy"/>=20
<catom name=3D"Person"/>=20
</impliesc>=20

<impliesc>=20
<catom name=3D"HappyMan"/>=20
<some>=20
<ratom name=3D"hasChild"/>=20
<catom name=3D"Boy"/>=20
</some>=20
</impliesc>=20

<impliesc>=20
<catom name=3D"Man"/>=20
<some>=20
<ratom name=3D"hasChild"/>=20
<catom name=3D"Person"/>=20
</some>=20
</impliesc>=20

the reasoner does not infer that "HappyMan" is subsumed by "Man". I =
thought it was basic, isn't i? I am not sure to really understand the =
reason why.

Best,=20

Freddy


________________________________

De : Krzysztof Goczyla [mailto:kr...@et...]=20
Envoy=E9 : vendredi 22 d=E9cembre 2006 10:54
=C0 : LECUE FREDDY RD-TECH-REN
Objet : Re: [DIG-users] Strange Inference Behaviour


Dear Freddy,
=20
The reason comes from the meaning of general quantification in FOL (and =
hence in DL):
=20
(ALL Role.Concept)  is equivalent to (NOT EXISTS Role.NOT Concept).
=20
According to your axioms on HappyMan and Man, both can have no children. =
So, you may divide concept Man (and also concept HappyMan) into two =
parts. In the first part there are individuals with children =
(ManWithChildren and HappyManWithChildren), in the second part =
individuals without children. For the first parts of course: =
HappyManWithChildren <impliesc> ManWithChildren, since any Boy is a =
Person; while for the second parts nothong tells us, that a HappyMan =
with no children is a Man with no children.
=20
Best
=20
Kris Goczyla
=20
=20
=20
=20
=20

	----- Original Message -----=20
	From: LECUE FREDDY RD-TECH-REN <mailto:fre...@or...> =
=20
	To: dig...@li...=20
	Cc: Ralf M=F6ller <mailto:r.f...@tu...>  ; Daniele Turi =
<mailto:dt...@cs...> =20
	Sent: Friday, December 22, 2006 9:19 AM
	Subject: [DIG-users] Strange Inference Behaviour


	Hi all,=20
	  Suppose the following simple Knowledge Base wherein "Boy", "Person", =
"Man" and "HappyMan" are 4 concepts.=20

	<impliesc>=20
	<catom name=3D"Boy"/>=20
	<catom name=3D"Person"/>=20
	</impliesc>=20

	<impliesc>=20
	<catom name=3D"HappyMan"/>=20
	<all>=20
	<ratom name=3D"hasChild"/>=20
	<catom name=3D"Boy"/>=20
	</all>=20
	</impliesc>=20

	<impliesc>=20
	<catom name=3D"Man"/>=20
	<all>=20
	<ratom name=3D"hasChild"/>=20
	<catom name=3D"Person"/>=20
	</all>=20
	</impliesc>=20

	  According to any reasoner (Fact++, cel) I use to interface the =
reasoning, when I ask if "Man" subsumes "HappyMan", the returned =
response is false!

	  What do You think about this behaviour? Do you have any explanation?=20

	Many thanks in advance.=20
	Best,=20
	Freddy=20

=09
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