- From: Richard Newman <r.newman@reading.ac.uk>
- Date: Sun, 5 Jun 2005 16:09:09 +0100
- To: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Cc: patrick.stickler@gmail.com, semantic-web@w3.org
On 5 Jun 2005, at 15:02, Peter F. Patel-Schneider wrote:
>> I.e. the subgraph contains statements about object bnodes if any such
>> statements exist. If it contains triples pointing to bnodes, and no
>> statements about those bnodes, it's because the original graph didn't
>> make any statements about those bnodes.
>
> This is not what is stated in the submission.
You're quite right, forgive my blurry eyes.
---
2. Recursively, for all statements identified in the
subgraph thus far having a blank node object, include in the subgraph
all statements in the source graph where the subject of the statement
is the blank node in question and which are not already included in
the subgraph.
---
This having been done, we end up with the graph in your email as both
the original graph and the subgraph:
x y _:1 .
x z a .
z b _:2 .
_:1 c d .
_:1 e "f" .
The submission continues:
---
This results in a subgraph where the object nodes are either URI
references, literals, or blank nodes not serving as the subject of
any statement in the [original] graph.
---
The object nodes in the subgraph are:
_:1, _:2, a, d, "f".
The assertion in the submission is true for "f", a, and d. In fact,
it's also true for _:2. However, it's not true for _:1. _:1 is an
object node, but it is also a blank node which serves as the subject
of a statement in the original graph.
The wording for the submission should be changed from "object nodes"
to "leaf nodes", which reflects the fact that _:1 has its associated
triples included in the subgraph, and is thus no longer a leaf node.
If additional clarity were desired, it should be made explicit that
any bnode in the subgraph that is not the subject of triples in the
subgraph must therefore not be the subject of triples in the original
graph.
Well spotted!
-R
Received on Sunday, 5 June 2005 15:09:24 UTC