| 释义 |
free group Given a set S, the free group F(S) is the set of words using elements x of S and their formal inverses x−1 with group operation being concatenation. Two distinct words are equal if and only if this involves replacing a product xx−1 or x−1x with the identity e or vice versa, that is, there are no non-trivial relations. Every group is a quotient group of a free group. See presentation.
|