> On 19 Jul 2019, at 20:36, John Clark <[email protected]> wrote: > > On Fri, Jul 19, 2019 at 1:33 PM Telmo Menezes <[email protected] > <mailto:[email protected]>> wrote: > > > How do you decide if something is a Turing Machine or not? > > X is a Turing Machine if and only if for any given input to X there exists a > Turing Machine that will produce the same output as X does with the same > input.
That works for a lambda expression to. But a Turing machine is NOT (literally) a lambda expression. A Turing machine is a set of quadruplets. You confuse the mathematical notion of Turing machine, with its general sense, which can be sued to say that any digital machine can be seen as a Turing machine, by labelling all its states, and construct the corresponding finite table (quadruplets), but we can do this for any Turing complete formalism, even if it is more pedagogical to use Turing’s formalisme for this. > > > Is Domino a Turing Machine? > > A Domino computer is. > > > What about my brain? > > It's a Turing Machine. > > > What about the billiard ball computer? > > It's a Turing Machine. > > > The only equivalence used in Computer Science is in completeness: Van > > Neumann Machines and GPUs are Turing Complete, in the sense that they are > > as general a computational device as a Turing Machine. > > Only?! If X is Turing Complete then a Turing Machine can emulate X and X can > emulate a Turing Machine. All universal machine/formalisme can emulate all universal machine/formalism. > > > I never heard or read anyone before claiming that Turing Machines are > > physically more fundamental, > > Do you know of anything simpler that can make calculations than read a > square, erase what you read and then print either a 0 or a 1 on it depending > on your state, then change into another state depending on what you read, > then either halt or move right or left and read another square. Yes, combinators are simpler, and lambda expression too. It is just simple substation. Can you imagine something simpler that K x y = x S x y z = x z (y z) ? Bruno > > John K Clark > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAJPayv2HL22OknRKijRMMjfFS5hBvq7r0eWpyEAhK1QuOC3jgA%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAJPayv2HL22OknRKijRMMjfFS5hBvq7r0eWpyEAhK1QuOC3jgA%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/0A47C571-F11C-4760-984B-C6A4BD209C74%40ulb.ac.be.
