On Sunday, July 21, 2019 at 2:48:49 PM UTC-5, John Clark wrote: > > > > On Sun, Jul 21, 2019 at 3:14 PM Philip Thrift <[email protected] > <javascript:>> wrote: > > A "machine" associated with the lambda calculus is the SECD machine >> https://en.wikipedia.org/wiki/SECD_machine >> <https://en.wikipedia.org/wiki/SECD_machine#Informal_description> >> The machine was the first to be specifically designed to evaluate lambda >> calculus <https://en.wikipedia.org/wiki/Lambda_calculus> expressions. >> > > And in the very first line of the article you recommend it calls it a > "virtual machine". There is nothing virtual about a read write head and a > paper tape, that sort of machine is as non-virtual as the diesel engine on > a tug boat. > > John K Clark >
*virtual, hypothetical, theoretical, abstract *- both the Turing machine and SECD machine are merely that. *No one in computer science refers to the Turing machine as an actual machine.* Turing machine, hypothetical computing device - https://www.britannica.com/technology/Turing-machine A Turing machine refers to a hypothetical machine proposed by Alan M. Turing - http://www.scholarpedia.org/article/Turing_machine A Turing machine is a theoretical computing machine - http://mathworld.wolfram.com/TuringMachine.html A Turing machine is a mathematical model of computation that defines an abstract machine, - https://en.wikipedia.org/wiki/Turing_machine @philipthrift -- 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/38a2519c-e0ec-48ee-abb7-bee0f8435fac%40googlegroups.com.
