> On 22 Jul 2019, at 15:46, John Clark <[email protected]> wrote: > > On Mon, Jul 22, 2019 at 3:54 AM Bruno Marchal <[email protected] > <mailto:[email protected]>> wrote: > > >> a set of quadruplets is not the only or the best way to think about the > >> operation of a Turing Machine, you can also think about it physically, > >> something that you CAN NOT DO with Lambda Calculus. > > > On the contrary, if you can interpret the quadruplet in a physical way, > > And you can. > > > then it is even more simple to interpret a lambda expression physically, > > with a basic physical substitution. > > Yes you can implement lambda expressions physically but it's not "more > simple" because the "basic physical substitution" always comes back to a > Turing Machine. Always.
Of course not. The substitution are realise by boolean graph directly. Nobody has ver implement anything in a physical implementations of a Turing machine. It just that we can see, even a human being (and assuming Mechanism) as a (very lose Turing machine, with the paper as tape, a pen as the read instruction, a eraser for the erasing instruction, and any distinguishable drawing for the alphabet, and all neural configuration of its brain for the machine’s state. I can call that a Turing machine when speaking losely in some context, but that is not a Turing machine is Turing mathematical definition of it. Bruno > > That's why computer makers don't put Lambda Calculus textbooks in their > machines but instead put in silicon microprocessors that work the way Turing > outlined. > > > Counter-examples; the graph reduction machines, the Lisp Machines, etc. > > Bruno..... I'm pretty sure both graph reduction machines and Lisp Machines > used silicon microprocessors, although they've been obsolete for so long it > might have been discreet transistors or even vacuum tubes. I don't know about > etc Machines, I'm not familiar with them. > > 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/CAJPayv0i7uDqjK%2BCTuZArPztB8TA0-KNG5u20h6WQa6MGT3nfQ%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAJPayv0i7uDqjK%2BCTuZArPztB8TA0-KNG5u20h6WQa6MGT3nfQ%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/F4BD6DB7-0585-4486-8241-3A3EC9E01E90%40ulb.ac.be.
