# 本书部分数学符号

 ${\displaystyle \in }$ ${\displaystyle x\in A}$ ${\displaystyle x}$ 属于${\displaystyle A}$ ；${\displaystyle x}$ 是集合${\displaystyle A}$ 的一个元素 ${\displaystyle \notin }$ ${\displaystyle y\notin A}$ ${\displaystyle y}$ 不属于${\displaystyle A}$ ；${\displaystyle y}$ 不是集合${\displaystyle A}$ 的一个元素 ${\displaystyle \left\{,\cdots ,\right\}}$ ${\displaystyle \left\{a,b,c,\cdots ,n\right\}}$ 诸元素${\displaystyle a,b,c,\cdots ,n}$ 构成的集合 ${\displaystyle \left\{|\right\}}$ ${\displaystyle \left\{x\in A|p\left(x\right)\right\}}$ 使命题${\displaystyle p\left(x\right)}$ 为真的${\displaystyle A}$ 中诸元素之集合 ${\displaystyle \varnothing }$ 空集 ${\displaystyle \mathbb {N} }$ 非负整数集；自然数集 ${\displaystyle \mathbb {N} ^{*}}$ 或${\displaystyle \mathbb {N} _{+}}$ 正整数集 ${\displaystyle \mathbb {Z} }$ 整数集 ${\displaystyle \mathbb {Q} }$ 有理数集 ${\displaystyle \mathbb {R} }$ 实数集 ${\displaystyle \subseteq }$ ${\displaystyle B\subseteq A}$ ${\displaystyle B}$ 含于${\displaystyle A}$ ；${\displaystyle B}$ 是${\displaystyle A}$ 的子集 ${\displaystyle \subsetneqq }$ ${\displaystyle B\subsetneqq A}$ ${\displaystyle B}$ 真包含于${\displaystyle A}$ ；${\displaystyle B}$ 是${\displaystyle A}$ 的真子集 ${\displaystyle \cup }$ ${\displaystyle A\cup B}$ ${\displaystyle A}$ 与${\displaystyle B}$ 的并集 ${\displaystyle \cap }$ ${\displaystyle A\cap B}$ ${\displaystyle A}$ 与${\displaystyle B}$ 的交集 ${\displaystyle \complement }$ ${\displaystyle \complement _{A}B}$ ${\displaystyle A}$ 中子集${\displaystyle B}$ 的补集或余集 ${\displaystyle \left[,\right]}$ ${\displaystyle \left[a,b\right]}$ ${\displaystyle \mathbb {R} }$ 中由${\displaystyle a}$ 到${\displaystyle b}$ 的闭区间 ${\displaystyle \left(,\right)}$ ${\displaystyle \left(a,b\right)}$ ${\displaystyle \mathbb {R} }$ 中由${\displaystyle a}$ 到${\displaystyle b}$ 的开区间 ${\displaystyle \left[,\right)}$ ${\displaystyle \left[a,b\right)}$ ${\displaystyle \mathbb {R} }$ 中由${\displaystyle a}$ （含于内）到${\displaystyle b}$ 的右半开区间 ${\displaystyle \left(,\right]}$ ${\displaystyle \left(a,b\right]}$ ${\displaystyle \mathbb {R} }$ 中由${\displaystyle a}$ 到${\displaystyle b}$ （含于内）的左半开区间 ${\displaystyle f\left(x\right)}$ 函数${\displaystyle f}$ 在${\displaystyle x}$ 的值 ${\displaystyle f:A\to B}$ 集合${\displaystyle A}$ 到集合${\displaystyle B}$ 的映射