Re: Two computer science professors agree with Flibble

On 2025-05-05 03:46:18 +0000, olcott said:

On 5/4/2025 10:40 PM, dbush wrote:

On 5/4/2025 11:35 PM, olcott wrote:

On 5/4/2025 10:18 PM, dbush wrote:

On 5/4/2025 11:10 PM, olcott wrote:

On 5/4/2025 10:00 PM, dbush wrote:

On 5/4/2025 9:38 PM, olcott wrote:

On 5/4/2025 8:13 PM, Ben Bacarisse wrote:

Richard Heathfield <rjh@cpax.org.uk> writes:
 

On 04/05/2025 23:34, Mr Flibble wrote:

The function is neither computable nor incomputable because there is no
function at all, just a category error.

 It's a point of view.

 It's a point of view only in the sense that there is no opinion so daft
that it's not someone's point of view.  The technical-sounding waffle
about it being a "category error" is simply addressed by asking where
the supposed category error is in other perfectly straightforward
undecidable problems.  For example, whether or not a context-free
grammar is ambiguous or not, or the very simple to pose Post
correspondence problem.
 

 Flibble IS CORRECT when the halting problem is defined
to be isomorphic (AKA analogous) to the Liar Paradox:
"This sentence is not true".
 When the Halting Problem is defined as an input that
does the opposite of whatever its decider reports
then both Boolean return values are incorrect

 False.  One value is correct and one is incorrect.
 

 Both Boolean RETURN VALUES FROM H *ARE* INCORRECT,

Category error.  Algorithms do one thing and one thing only.  And the algorithm that is the fixed code of the function H and everything it calls gives the wrong answer, and the opposing answer is the right answer.

 Look at the paper from the PhD computer science
professor.
 Halting misconceived?
Bill Stoddart
August 25, 2017
 *the halting function, as described, cannot be implemented*,
*because its specication is inconsistent*...
 *Context*
That halting is not in general computable has been
proved in many text books and taught on many computer
science courses, and is supposed to illustrate the
limits of computation. However, there is a dissenting
view that these proofs are misconceived.
 In this paper we look at what is perhaps the simplest
such proof, based on a program that interrogates its own
halting behaviour and then decides to thwart it. This
leads to a contradiction that is generally held to show
that a halting function cannot be implemented.
 The dissenting view agrees with the conclusion that
*the halting function, as described, cannot be implemented*,
but suggests that this is *because its specication is inconsistent*
https://www.complang.tuwien.ac.at/anton/euroforth/ef17/papers/ stoddart.pdf

 The only way for the specification to be inconsistent if there was an algorithm, i.e. a fixed immutable sequence of instructions, that neither halts nor not halts when executed directly.

 OK now we get down to the nuances.
 The way that meaning in language actually works
as understood by linguistics: The context of
who as asked a question <is> an aspect of the
full meaning of this question.

Linguistic meanings include a lot more than mathematical an computational
meanings. Mathematical and computational meanings do not depend on who is
asked.
--
Mikko