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OpenLogicProject / fitch-checker

JavaScript/PHP Fitch-style natural deduction proof editor and checker (NO LONGER MAINTAINED)
GNU General Public License v3.0
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Divergence #15

Open gimenes2008 opened 1 year ago

gimenes2008 commented 1 year ago

Hi!

I found this divergence:

image

In other systems the conclusion is valid:

image

Source: https://www.umsu.de/trees/

image

_Source: https://www.taut-logic.com/predicate_nd.html_

frabjous commented 1 year ago

This does look like a bug, but this isn't really an active project any more. It was more of a proof of concept back when I created it. I am working on a new system, and I'll try to make sure it handles this correctly, so I don't think it's worth making any changes to the old system.

gimenes2008 commented 1 year ago

This does look like a bug, but this isn't really an active project any more. It was more of a proof of concept back when I created it. I am working on a new system, and I'll try to make sure it handles this correctly, so I don't think it's worth making any changes to the old system.

I understand.