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Question about turing machine

  1. Sep 18, 2013 #1
    I read many articles about turing machine,but i still confused:confused:

    is a turing machine can only execute one program(hardwired) ?
    or it can execute many programs(like a conventional computer)?

    i asking about turing machine as shown in figure blew(not asking about universal TM ):
  2. jcsd
  3. Sep 18, 2013 #2
    Delta (item 4) is sometimes called the "table."
    That is equivalent to a program you would write for a computer.

    I don't remember distinguishing "input symbols" from "tape symbols."
    The tape is equivalent to the input and output for a computer.

    So you could write any "program" and fill the table, which is you defining delta.
    That program could then accept any input on the tape and produce the output on the tape.

    Does that help?
  4. Sep 19, 2013 #3
    yes that help,
    but if the turing machine can execute any "program",
    that mean it can simulate any other turing machine ,
    so that mean any turing machine we can called it universal turing machine!!!
  5. Sep 19, 2013 #4
  6. Sep 19, 2013 #5

    D H

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    Staff Emeritus
    Science Advisor

    A Turing machine is not necessarily able to execute any "program". What if the table (δ) is hard-wired? That one program can be swapped out for another is the key distinguishing feature between a universal Turing machine and a plain ordinary Turing machine.
  7. Sep 19, 2013 #6
    that help,thank you:smile:
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