• Re: How halt is defined

    From Mikko@mikko.levanto@iki.fi to comp.theory on Thu Sep 11 12:01:56 2025
    From Newsgroup: comp.theory

    On 2025-09-10 11:31:00 +0000, olcott said:

    Eventually, the whole process may terminate,
    which we achieve in a Turing machine by putting
    it into a halt state. A Turing machine is said
    to halt whenever it reaches a configuration for
    which δ is not defined; this is possible because
    δ is a partial function. In fact, we will assume
    that no transitions are defined for any final
    state, so the Turing machine will halt whenever
    it enters a final state. page 1990:234 Linz

    Linz, Peter 1990. An Introduction to Formal Languages and Automata. Lexington/Toronto: D. C. Heath and Company. (317-320)

    I stated in news:109ojic$ract$1@dont-email.me that "About Turing
    machines it means a configuration for which the rules don't specfy
    any action." Above Linz says the same.
    --
    Mikko

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  • From olcott@polcott333@gmail.com to comp.theory on Thu Sep 11 10:48:42 2025
    From Newsgroup: comp.theory

    On 9/11/2025 4:01 AM, Mikko wrote:
    On 2025-09-10 11:31:00 +0000, olcott said:

    Eventually, the whole process may terminate,
    which we achieve in a Turing machine by putting
    it into a halt state. A Turing machine is said
    to halt whenever it reaches a configuration for
    which δ is not defined; this is possible because
    δ is a partial function. In fact, we will assume
    that no transitions are defined for any final
    state, so the Turing machine will halt whenever
    it enters a final state. page 1990:234 Linz

    Linz, Peter 1990. An Introduction to Formal Languages and Automata.
    Lexington/Toronto: D. C. Heath and Company. (317-320)

    I stated in news:109ojic$ract$1@dont-email.me that "About Turing
    machines it means a configuration for which the rules don't specfy
    any action." Above Linz says the same.


    And also says the Turing machine will halt whenever
    it enters a final state.

    Then Jeff from this group says all this:

    On 8/2/2024 11:32 PM, Jeff Barnett wrote:
    On 8/2/2024 7:19 PM, Mike Terry wrote:

    Definition: A TM P given input I is said to "halt" iff ?????
    or whatever...

    I think this is a rather hopeless venture without
    formally defining the representation of a TM. For
    example: In some formulations, there are specific
    states defined as "halting states" and the machine
    only halts if either the start state is a halt state or
    there is a transition to a halt state within the execution
    trace; In another formulation, machines halt if there
    is a transition to an undefined state. Note a few things:
    1) the if's above are really iff's, 2) these and many
    other definitions all have equivalent computing prowess,
    3) Some formulations define results by what is left on
    the tape (or other storage device) while others add the
    actual halting state to determine the results.

    In a conversation about such topics, gentlemen of good
    faith and reasonable knowledge can simple ignore these
    differences and not go off the rails.
    --
    Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius
    hits a target no one else can see." Arthur Schopenhauer
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  • From Mikko@mikko.levanto@iki.fi to comp.theory on Fri Sep 12 09:34:08 2025
    From Newsgroup: comp.theory

    On 2025-09-11 15:48:42 +0000, olcott said:

    On 9/11/2025 4:01 AM, Mikko wrote:
    On 2025-09-10 11:31:00 +0000, olcott said:

    Eventually, the whole process may terminate,
    which we achieve in a Turing machine by putting
    it into a halt state. A Turing machine is said
    to halt whenever it reaches a configuration for
    which δ is not defined; this is possible because
    δ is a partial function. In fact, we will assume
    that no transitions are defined for any final
    state, so the Turing machine will halt whenever
    it enters a final state. page 1990:234 Linz

    Linz, Peter 1990. An Introduction to Formal Languages and Automata.
    Lexington/Toronto: D. C. Heath and Company. (317-320)

    I stated in news:109ojic$ract$1@dont-email.me that "About Turing
    machines it means a configuration for which the rules don't specfy
    any action." Above Linz says the same.

    And also says the Turing machine will halt whenever
    it enters a final state.

    That is obvious when "final state" is defined as a state where
    the Turing machine halts.

    But Linz does not say that as a part of the definition of halting.
    After the definition he says he assumes that in his Turing machine
    every state has rules for either every or no tape symbol. Other
    author permit and in some cases requite that a Turing machine has
    a state that has a rule for some but not all possible tape symbols,
    and call such states as "reject" states.

    But in any case, as Linz says, "said to halt whenever it reaches a configuration for which δ is not defined", where δ is the partial
    function that determines the next configuration of the Turing
    machine. That agrees with the usual meaning of "halt".
    --
    Mikko

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  • From olcott@polcott333@gmail.com to comp.theory on Fri Sep 12 08:43:04 2025
    From Newsgroup: comp.theory

    On 9/12/2025 1:34 AM, Mikko wrote:
    On 2025-09-11 15:48:42 +0000, olcott said:

    On 9/11/2025 4:01 AM, Mikko wrote:
    On 2025-09-10 11:31:00 +0000, olcott said:

    Eventually, the whole process may terminate,
    which we achieve in a Turing machine by putting
    it into a halt state. A Turing machine is said
    to halt whenever it reaches a configuration for
    which δ is not defined; this is possible because
    δ is a partial function. In fact, we will assume
    that no transitions are defined for any final
    state, so the Turing machine will halt whenever
    it enters a final state. page 1990:234 Linz

    Linz, Peter 1990. An Introduction to Formal Languages and Automata.
    Lexington/Toronto: D. C. Heath and Company. (317-320)

    I stated in news:109ojic$ract$1@dont-email.me that "About Turing
    machines it means a configuration for which the rules don't specfy
    any action." Above Linz says the same.

    And also says the Turing machine will halt whenever
    it enters a final state.

    That is obvious when "final state" is defined as a state where
    the Turing machine halts.

    But Linz does not say that as a part of the definition of halting.
    After the definition he says he assumes that in his Turing machine
    every state has rules for either every or no tape symbol. Other
    author permit and in some cases requite that a Turing machine has
    a state that has a rule for some but not all possible tape symbols,
    and call such states as "reject" states.

    But in any case, as Linz says, "said to halt whenever it reaches a configuration for which δ is not defined", where δ is the partial
    function that determines the next configuration of the Turing
    machine. That agrees with the usual meaning of "halt".


    This is our own Jeff, make sure you read his
    last paragraph

    On 8/2/2024 11:32 PM, Jeff Barnett wrote:
    On 8/2/2024 7:19 PM, Mike Terry wrote:

    Definition: A TM P given input I is said to "halt" iff ?????
    or whatever...

    I think this is a rather hopeless venture without
    formally defining the representation of a TM. For
    example: In some formulations, there are specific
    states defined as "halting states" and the machine
    only halts if either the start state is a halt state or
    there is a transition to a halt state within the execution
    trace; In another formulation, machines halt if there
    is a transition to an undefined state. Note a few things:
    1) the if's above are really iff's, 2) these and many
    other definitions all have equivalent computing prowess,
    3) Some formulations define results by what is left on
    the tape (or other storage device) while others add the
    actual halting state to determine the results.

    In a conversation about such topics, gentlemen of good
    faith and reasonable knowledge can simple ignore these
    differences and not go off the rails.
    --
    Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius
    hits a target no one else can see." Arthur Schopenhauer
    --- Synchronet 3.21a-Linux NewsLink 1.2
  • From Mikko@mikko.levanto@iki.fi to comp.theory on Sat Sep 13 11:51:48 2025
    From Newsgroup: comp.theory

    On 2025-09-12 13:43:04 +0000, olcott said:

    On 9/12/2025 1:34 AM, Mikko wrote:
    On 2025-09-11 15:48:42 +0000, olcott said:

    On 9/11/2025 4:01 AM, Mikko wrote:
    On 2025-09-10 11:31:00 +0000, olcott said:

    Eventually, the whole process may terminate,
    which we achieve in a Turing machine by putting
    it into a halt state. A Turing machine is said
    to halt whenever it reaches a configuration for
    which δ is not defined; this is possible because
    δ is a partial function. In fact, we will assume
    that no transitions are defined for any final
    state, so the Turing machine will halt whenever
    it enters a final state. page 1990:234 Linz

    Linz, Peter 1990. An Introduction to Formal Languages and Automata. >>>>> Lexington/Toronto: D. C. Heath and Company. (317-320)

    I stated in news:109ojic$ract$1@dont-email.me that "About Turing
    machines it means a configuration for which the rules don't specfy
    any action." Above Linz says the same.

    And also says the Turing machine will halt whenever
    it enters a final state.

    That is obvious when "final state" is defined as a state where
    the Turing machine halts.

    But Linz does not say that as a part of the definition of halting.
    After the definition he says he assumes that in his Turing machine
    every state has rules for either every or no tape symbol. Other
    author permit and in some cases requite that a Turing machine has
    a state that has a rule for some but not all possible tape symbols,
    and call such states as "reject" states.

    But in any case, as Linz says, "said to halt whenever it reaches a
    configuration for which δ is not defined", where δ is the partial
    function that determines the next configuration of the Turing
    machine. That agrees with the usual meaning of "halt".

    This is our own Jeff, make sure you read his
    last paragraph

    On 8/2/2024 11:32 PM, Jeff Barnett wrote:
    On 8/2/2024 7:19 PM, Mike Terry wrote:

    Definition: A TM P given input I is said to "halt" iff ?????
    or whatever...

    I think this is a rather hopeless venture without
    formally defining the representation of a TM. For
    example: In some formulations, there are specific
    states defined as "halting states" and the machine
    only halts if either the start state is a halt state or
    there is a transition to a halt state within the execution
    trace; In another formulation, machines halt if there
    is a transition to an undefined state. Note a few things:
    1) the if's above are really iff's, 2) these and many
    other definitions all have equivalent computing prowess,
    3) Some formulations define results by what is left on
    the tape (or other storage device) while others add the
    actual halting state to determine the results.

    In a conversation about such topics, gentlemen of good
    faith and reasonable knowledge can simple ignore these
    differences and not go off the rails.

    A good answer to the question on the subject line, and in full
    agreement with my answer to the same.
    --
    Mikko

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