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It is quite unreasonable to talk about variables that change with time in the context of a Turing machine. If a "Universal Computer" is one that deals with variables which change during the computation due to interaction, then it is not what Turing was talking about. And if he wasn't talking about it, he can't be wrong about it.

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The argument isn't about computing, it's about naming. The argument here is whether a Turing machine is really "universal".

It's naming, plus some more: Turing never named his idealized entity a "Turing machine" - that was done by others. He claimed universality for the algorithmic "Universal Computing Machine" he defined, and proved it - for algorithms. Now Akl comes along and says the "Turing machine" is not universal, but he uses interaction, not algorithm, to base his definition of computation on. So it seems to me that he's not only renaming "the Universal Computing Machine" to "the Universal Computer" by ways of "the Turing Machine", but that he is also moving the goalposts in this process.

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