# ⓘ 单位群

## ⓘ 单位群

## 1. 单位

O K ≃ {\displaystyle \simeq } Z ⊕r ⊕（有限循环群）。

## 2. 例子

Q7:=QuadraticField-11;Q7; O7:=MaximalOrderQ7;O7; DiscriminantQ7 ; ClassGroupQ7; a:=O7!5;a; aa:=O7!500;aa; Factorizationa; Factorizationaa; Q17:=QuadraticField17;Q17; FundamentalUnitQ17; DiscriminantQ17 ; ClassGroupQ17; Quadratic Field with defining polynomial \$.1^2 + 11 over the Rational Field Maximal Order of Q7 -11 Abelian Group of order 1 Mapping from: Abelian Group of order 1 to Set of ideals of O7 5 500 Quadratic Field with defining polynomial \$.1^2 - 17 over the Rational Field -Q17.1 + 4 17 Abelian Group of order 1 Mapping from: Abelian Group of order 1 to Set of ideals of Maximal Order of Q17