question on "forest-like anonymous individuals" restriction of OWL 2 DL

Hi all!

I had to explain to someone the "forest-like anonymous individuals" restriction of OWL 2 DL (Section 11.2 of the Structural Spec), but I found myself uncertain about it. In particular, I'm unclear how "fixed" the variable "OPE" is in the set of conditions.

But it's easier to show my problem by an example: It's clear to me (also from the example following the formal definition) that the following is /not/ allowed in OWL 2 DL:

  _:x :p _:y
  _:y :p _:x

But what about

  _:x :p _:y
  _:y :q _:x

with /different/ properties?

Michael

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Dipl.-Inform. Michael Schneider
Research Scientist, Dept. Information Process Engineering (IPE)
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Fax  : +49-721-9654-727
Email: michael.schneider@fzi.de
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