Reverse Turing test a computer is then said to "pass the Turing test" if it is also judged human. Any of these roles may be changed to form a "reverse Turing test". Arguably the standard form of the reverse Turing test is one in which the subjects attempt to appear to be a computer rather than a human. A formal reverse Turing test follows the same format as a Turing test. Human subjects attempt to imitate the conversational style of a conversation program such as ELIZA. Doing this well involves deliberately ignoring, to some degree, the meaning of the conversation that is immediately
Turing completeness an algorithm can be computed by a Turing machine, and therefore that if any real-world computer can simulate a Turing machine, it is Turing equivalent to a Turing machine. A universal Turing machine can be used to simulate any Turing machine and by extension the computational aspects of any possible real-world computer. To show that something is Turing complete, it is enough to show that it can be used to simulate some Turing complete system. For example, an imperative language is Turing complete if it has conditional branching ("e.g.", "if" and "goto" statements, or a "branch if zero" instruction; see