With this done, it followed that one particular machine could simulate the work done by any machine. He called it the universal machine.
这个问题解决了,下一个问题是,需要一个机器来模拟其它任何机器的工作。艾伦称之为通用机器。
It would be designed to read description numbers, decode them into tables, and execute them.
它要先读出描述数,解码成行为表,然后运行。
It could do what any other machine would have done, if it were provided with the description number of that machine on its tape.
只要给它提供另一个机器的描述数,它就能做把它们编译成表并执行。
It would be a machine to do everything, which was enough to give anyone pause for thought.
它可以做任何一个机器能做的事,只要告诉它那个机器的描述数。
It was, furthermore, a machine of perfectly definite form. Alan worked out an exact table for the universal machine.
它是一个能做任何事情的机器,足以让人叹为观止。更重要的是,它有着非常明确的形式,艾伦设计出了通用机器的行为表。
This was not the trouble with mechanising the Cantor process.
现在对于康托机来说,这也不是麻烦。
The difficulty lay in the other requirement, that of producing the tables, in their 'alphabetical order', for the computable numbers.
还有一个问题是,对于一个可计算数的列表,如何按顺序为其中的每个数编写行为表。
Suppose that the tables were encoded as description numbers. In practice, they would not use up all the integers;
如果把这些运行表编码成描述数的话,它们并不会按顺序用到每一个整数。
in fact, the system Alan devised would encode even the simplest tables into enormous numbers.
实际上,在艾伦设计的系统中,即使是最简单的运行表,也会编码成一个非常大的描述数。
But that would not matter. It would be essentially a 'mechanical' matter to work through the integers in turn, and to pass over those which did not correspond to proper tables. That was a technicality, almost a matter of notation.
但这也并不要紧,只需要通过一个机械的过程,按顺序逐个处理每个整数,把那些"不能代表合法的行为表的数"跳过去就行了,这也只是技术问题。
The real problem was more subtle.
然而,真正的问题,反倒看上去更加微不足道。
The question was this: given (say) the 4589th properly defined table, how could one tell that it would produce a 4589th digit?
比如,现在遇到了第4589个合法的行为表,你怎么判断它能不能产生第4589个数字?
Or indeed, that it would produce any digits at all?
或者说,你怎么判断它能不能产生数字?
It might trundle back and forth in a repeated cycle of operations for ever, without producing more figures.
没准它会陷入死循环,根本不会产生数字,
It this were the case, the Cantor machine would be stuck, and could never finish its job.
然后整个康托机就卡壳了,永远无法完成它的工作。