Post's Machine. **A Sort of 'Pre-Turing Machine'**

Uspensky, V.A. Post's Machine. Little Mathematics Library series from the (formerly) gigantic Mir publishing enterprise in Moscow. First appearance in English following the 1979 Russian amendments. 9X5.5", 88pp. Wrappers. VG copy. 1983. There's some sort of old fold in the cover that you can see in the photo--it actually looks like a tree and part of the design of the book (to me) but it isn't; looks better in-hand than in the photo. Emil Post's "Post machine" was not a physical computer in the ordinary sense, but a very simple abstract model of computation developed in mathematical logic during the 1930s. It was closely related to what later became known as the Turing machine. "A Post machine or Post-Turing machine is a "program formulation" of a type of Turing machine, comprising a variant of Emil Post's Turing-equivalent model of computation. Post's model and Turing's model, though very similar to one another, were developed independently. Turing's paper was received for publication in May 1936, followed by Post's in October. A Post-Turing machine uses a binary alphabet, an infinite sequence of binary storage locations, and a primitive programming language with instructions for bi-directional movement among the storage locations and alteration of their contents one at a time." 714.3.…