As a bijection from a set to itself, a permutation is a function that performs a rearrangement of a set, termed an active permutation or substitution. An older viewpoint sees a permutation as an …

In English we use the word combination loosely, without thinking if the order of things is important. In other words:

排列（permutation），数学的重要概念之一。 有限集 的子集按某种条件的序化法排成列、排成一圈、不许重复或许重复等。

permutation noun (DIFFERENT WAY/FORM) Add to word list [ C usually plural ] formal any of the various ways in which a set of things can be ordered

Nov 28, 2025 · Permutations and combinations, the various ways in which objects from a set may be selected, generally without replacement, to form subsets. This selection of subsets is called …

Oct 15, 2025 · In Mathematics, a Permutation is defined as a mathematical concept that determines the number of possible arrangements for a specific set of elements. Therefore, it …

2 days ago · In combinatorics, a permutation is an ordering of a list of objects. For example, arranging four people in a line is equivalent to finding permutations of four objects.

一般的说， 排列 (permutation)：从大小为 n 的 样本空间 中，抽取出大小为 r 的子集的个数，记为 (n r) 。 详细的说，排列的定义是“无重复”抽取“无序样本“，即不能再去排列子集的元素了。

5 days ago · A permutation, also called an "arrangement number" or "order," is a rearrangement of the elements of an ordered list into a one-to-one correspondence with itself.

排列 （英語： Permutation）又称 置換，是將相異物件或符號根據確定的順序重排，得到的每個順序都稱作一個 排列。 例如，從1到6的 數字 有720種排列，對應於由這些數字組成的所有不重 …