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ha-mo-we / Racer

Racer is a knowledge representation system that implements a highly optimized tableau calculus for the description logic SRIQ(D).
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Racer gets into a loop with these inconsistent files #10

Open fcbr opened 9 years ago

fcbr commented 9 years ago

Using these simple (but inconsistent) RDFs throws Racer into a loop. What I mean by that is that Racer pins the CPU to 100% for a couple of hours (so far), and doesn't return any result.

How to reproduce, (owl-read-file "<file>") and then (check-abox-coherence).

If you want to know what are the TBOX and ABOX, you can see them here

ha-mo-we commented 9 years ago

Thanks Fabricio, for reporting the problem.

I tried (abox-consitent?) and the answer NIL was shown immediately. However, (check-abox-coherence) causes the system to hang. We will look into this.

Regards, Ralf

On 27.08.2015, at 18:15, Fabricio Chalub notifications@github.com wrote:

Using these simple (but inconsistent) RDFs throws Racer into a loop. What I mean by that is that Racer pins the CPU to 100% for a couple of hours (so far), and doesn't return any result.

all-test-invalid-1.rdf: https://gist.github.com/fcbr/470b73a99c7dd818df15 https://gist.github.com/fcbr/470b73a99c7dd818df15 all-test-invalid-2.rdf: https://gist.github.com/fcbr/e01f8293f3fe8a3d5a64 https://gist.github.com/fcbr/e01f8293f3fe8a3d5a64 How to reproduce, (owl-read-file "") and then (check-abox-coherence).

If you want to know what are the TBOX and ABOX, you can see them here

TBOX for both files: https://gist.github.com/fcbr/62f12fecaed593ac1208 https://gist.github.com/fcbr/62f12fecaed593ac1208 ABOX for all-test-invalid-1.rdf: https://gist.github.com/fcbr/cd5b4a8444348ad06254 https://gist.github.com/fcbr/cd5b4a8444348ad06254 ABOX for all-test-invalid-2.rdf: https://gist.github.com/fcbr/2774c184fefd4a507de3 https://gist.github.com/fcbr/2774c184fefd4a507de3 — Reply to this email directly or view it on GitHub https://github.com/ha-mo-we/Racer/issues/10.

arademaker commented 5 years ago

Sorry , but I didn’t see new commit. Are you closing the issue before the fix? Don’t you think would be better to keep it open until we really have a solution? Closing it with a reference to the commit hash ?

ha-mo-we commented 5 years ago

Hi Alexandre,

Sorry for having been too eager closing the issue. The problem is that (check-abox-coherence) provides explanation facilities (see the second result term).

? (in-knowledge-base test) NIL ? (implies a b) A ? (instance i (not b)) ? (instance i a) ? (check-abox-coherence) (NIL ((I A) (:INFERENCE-STEP :ASSERTION (I A) :AXIOM (IMPLIES A B)) (I (NOT B))))

However, computing abox consistency with explanation for the larger example you provide is very very costly because the search space is very large. It could be a bug, but I strongly believe it is just the enormous search space that causes the apparent tight loop. The form abox-consistent? immediately returns nil (for not consistent) for your example (as indicated in my previous answer). The function check-abox-coherence is experimental.

Best regards, Ralf

On 8. Jul 2019, at 22:13, Alexandre Rademaker notifications@github.com wrote:

Sorry , but I didn’t see new commit. Are you closing the issue before the fix? Don’t you think would be better to keep it open until we really have a solution? Closing it with a reference to the commit hash ?

— You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub https://github.com/ha-mo-we/Racer/issues/10?email_source=notifications&email_token=AB2476US6LPON4PVLRDTNXLP6ONUZA5CNFSM4BONZML2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODZOG4QQ#issuecomment-509374018, or mute the thread https://github.com/notifications/unsubscribe-auth/AB2476TDA6SIWWBENZUVZ4LP6ONUZANCNFSM4BONZMLQ.

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ha-mo-we commented 5 years ago

Actually, it is Fabricio's example.