Undecidable problem

（重定向自Unsolvable problem）

In computability theory and computational complexity theory, an undecidable problem is a decision problem for which it is known to be impossible to construct a single algorithm that always leads to a correct yes-or-no answer.

A decision problem is any arbitrary yes-or-no question on an infinite set of inputs. Because of this, it is traditional to define the decision problem equivalently as the set of inputs for which the problem returns yes. These inputs can be natural numbers, but also other values of some other kind, such as strings of a formal language. Using some encoding, such as a Gödel numbering, the strings can be encoded as natural numbers. Thus, a decision problem informally phrased in terms of a formal language is also equivalent to a set of natural numbers. To keep the formal definition simple, it is phrased in terms of subsets of the natural numbers.

单词	Unsolvable problem
释义	Unsolvable problem 原声例句 Vox 观点 For a long time, heavy industries like cement seemed like unsolvable climate problems. 长期以来，水泥等重工业似乎是无法解决的气候问题。美国生活Podcast Like Boston's own Matt Damon in Good Will Hunting, she begins solving the unsolvable problem. 就像《心灵捕手》中波士顿的马特·达蒙一样，她开始解决这个无法解决的问题。英语百科 Undecidable problem （重定向自Unsolvable problem） In computability theory and computational complexity theory, an undecidable problem is a decision problem for which it is known to be impossible to construct a single algorithm that always leads to a correct yes-or-no answer. A decision problem is any arbitrary yes-or-no question on an infinite set of inputs. Because of this, it is traditional to define the decision problem equivalently as the set of inputs for which the problem returns yes. These inputs can be natural numbers, but also other values of some other kind, such as strings of a formal language. Using some encoding, such as a Gödel numbering, the strings can be encoded as natural numbers. Thus, a decision problem informally phrased in terms of a formal language is also equivalent to a set of natural numbers. To keep the formal definition simple, it is phrased in terms of subsets of the natural numbers.
随便看	pulse back edge的意思 pulseband的意思 pulse band的意思 pulse bandwidth的意思 pulse bandwidth filtering的意思 pulse base的意思 pulse base center point的意思 pulse base distortion的意思 pulse base magnitude的意思 pulsebeat的意思 pulse beat的意思 pulse beating的意思 pulse beating gently and regularly的意思 pulsebeats的意思 pulse beetle的意思 pulse being tense at both yin and yang locations的意思 pulse biasing的意思 pulse bleaching的意思 pulse blocking的意思 pulse blocking counter的意思 pulse broadening的意思 pulse broading的意思 pulse bucking adder的意思 pulse burst的意思 pulse bus的意思