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第72行：
第72行： − 实物描述+ 第78行：
第78行： − 在他1948年的论文《智能机器》中，Turing写道他的机器包括:+ 第128行：
第128行： − 更明确地说，图灵机由以下部分组成:+ 第136行：
第136行： − 磁头，可以在磁带上读写符号，并一次向左和向右移动磁带一格（也只有一格）。在某些型号中，磁头会移动，而磁带是静止的。+
→Physical description
===Physical description===
===Physical description===
实体描述
In his 1948 essay, "Intelligent Machinery", Turing wrote that his machine consisted of:
In his 1948 essay, "Intelligent Machinery", Turing wrote that his machine consisted of:
In his 1948 essay, "Intelligent Machinery", Turing wrote that his machine consisted of:
In his 1948 essay, "Intelligent Machinery", Turing wrote that his machine consisted of:
在他1948年的论文《智能机器》中，Turing写道，他的机器包括:
{{quote|...an unlimited memory capacity obtained in the form of an infinite tape marked out into squares, on each of which a symbol could be printed. At any moment there is one symbol in the machine; it is called the scanned symbol. The machine can alter the scanned symbol, and its behavior is in part determined by that symbol, but the symbols on the tape elsewhere do not affect the behavior of the machine. However, the tape can be moved back and forth through the machine, this being one of the elementary operations of the machine. Any symbol on the tape may therefore eventually have an innings.<ref>See the definition of "[[wikt:innings|innings]]" on [[Wiktionary]]</ref>|Turing 1948, p. 3<ref>
{{quote|...an unlimited memory capacity obtained in the form of an infinite tape marked out into squares, on each of which a symbol could be printed. At any moment there is one symbol in the machine; it is called the scanned symbol. The machine can alter the scanned symbol, and its behavior is in part determined by that symbol, but the symbols on the tape elsewhere do not affect the behavior of the machine. However, the tape can be moved back and forth through the machine, this being one of the elementary operations of the machine. Any symbol on the tape may therefore eventually have an innings.<ref>See the definition of "[[wikt:innings|innings]]" on [[Wiktionary]]</ref>|Turing 1948, p. 3<ref>
More explicitly, a Turing machine consists of:
More explicitly, a Turing machine consists of:
更切确地说，图灵机由以下部分组成:
* A ''tape'' divided into cells, one next to the other. Each cell contains a symbol from some finite alphabet. The alphabet contains a special blank symbol (here written as '0') and one or more other symbols. The tape is assumed to be arbitrarily extendable to the left and to the right, so that the Turing machine is always supplied with as much tape as it needs for its computation. Cells that have not been written before are assumed to be filled with the blank symbol. In some models the tape has a left end marked with a special symbol; the tape extends or is indefinitely extensible to the right.
* A ''tape'' divided into cells, one next to the other. Each cell contains a symbol from some finite alphabet. The alphabet contains a special blank symbol (here written as '0') and one or more other symbols. The tape is assumed to be arbitrarily extendable to the left and to the right, so that the Turing machine is always supplied with as much tape as it needs for its computation. Cells that have not been written before are assumed to be filled with the blank symbol. In some models the tape has a left end marked with a special symbol; the tape extends or is indefinitely extensible to the right.
* A ''head'' that can read and write symbols on the tape and move the tape left and right one (and only one) cell at a time. In some models the head moves and the tape is stationary.
* A ''head'' that can read and write symbols on the tape and move the tape left and right one (and only one) cell at a time. In some models the head moves and the tape is stationary.
磁头，可以在磁带上读写符号，并一次向左和向右移动磁带一格（也只有一格）。在某些模型中，磁头会移动，而磁带是静止的。
* A ''state register'' that stores the state of the Turing machine, one of finitely many. Among these is the special ''start state'' with which the state register is initialized. These states, writes Turing, replace the "state of mind" a person performing computations would ordinarily be in.
* A ''state register'' that stores the state of the Turing machine, one of finitely many. Among these is the special ''start state'' with which the state register is initialized. These states, writes Turing, replace the "state of mind" a person performing computations would ordinarily be in.