图灵机
This will prove that a two-track Turing machine is equivalent to a standard Turing machine. This can be generalized to a n-track Turing machine. Let L be a recursively enumerable language. Let M= formula_13 be standard Turing machine that accepts L. Let M' is a two-track Turing machine. To prove M=M' it must be shown that M formula_14 M' and M' formula_14 M