Unformatted text preview: beyond the left margin, a new blank cell is created to allow moving left. In this problem you are asked to give a formal deﬁnition of this extended Turing machine, including 1. the deﬁnition of a machine as a tuple of sets and functions 2. an appropriate set of conﬁgurations 3. an appropriate transition relation between conﬁgurations 4. the set of strings accepted by the machine Problem 3 Prove that the model of computation deﬁned in problem 2 is not more powerful than the Turing machine as deﬁned in the textbook, giving a method to transform any extended Turing machine (with doubly inﬁnite tape) into an equivalent regular Turing machine. Describe your transformation in detail, either by giving a formal description of the resulting Turing machine, or by providing an accurate low level description of all the steps it performs....
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- Fall '10
- Alan Turing, Random access machine, Daniele Micciancio