Re: Professor Eric Hehner's brilliant work --- isomorphisms

On 4/21/25 4:27 PM, olcott wrote:

WST Workshop on Termination, Oxford, 2018
Objective and Subjective Specifications
Eric C.R. Hehner
Department of Computer Science, University of Toronto
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(6) Can Carol correctly answer “no” to this (yes/no) question?
https://www.cs.toronto.edu/~hehner/OSS.pdf
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Is the perfect example of isomorphism to the halting problem's pathological input. The halting problem input D derives a self- contradictory question for H the same way that Carol's question
is self-contradictory for Carol.

 No it isn't, as Carol is a voltional being while a decider is deterministic.
 

Thus, the decider has effectively already made its decision on the input before the input is actually made, and thus the input can use that answer to thwart it.
 This just shows a category error in your logic. You don't seem to understand the deterministic behavior of programs, and the fact that all their behavior is created as soon as the program is created, even if they are never actually run or simulated. We just don't know what that behavior is.
 This goes back to another of your confusions, about the difference between Truth (which just is or isn't) and Knowledge, which might not be yet.
 

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Credit to Richard Damon for finding the loophole in the original question.
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Professor Eric Hehner PhD put the finishing touches on an
earlier idea in serial collaboration with  Daryl McCullough.
I quoted Daryl's work many many times without attribution
before I finally found this original post:
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    You ask someone (we'll call him "Jack") to give a truthful
    yes/no answer to the following question:
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    Will Jack's answer to this question be no?
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    Jack can't possibly give a correct yes/no answer to the question.
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    https://groups.google.com/g/sci.logic/c/4kIXI1kxmsI/m/hRroMoQZx2IJ
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