> For the complete documentation index, see [llms.txt](https://ayakaleaf-pro.ayaka.space/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ayakaleaf-pro.ayaka.space/latex/zh-cn/shu-xue/12-mathematical-fonts.md).

# 数学字体

## 引言

某些数学元素需要使用包含特定样式字符/符号的字体进行排版；例如，通常用黑板粗体字体表示实数（如 $$\mathbb{R}$$），或用花体字体表示拓扑空间（如（$$\mathcal{T}$$）。本文将以以下示例说明在数学排版中如何使用不同的字体样式：

```latex
设 \( \mathcal{T} \) 为一个拓扑空间，则基定义为
\[
 \mathcal{B} = \{B_{\alpha} \in \mathcal{T}\, |\,  U = \bigcup B_{\alpha} \forall U \in \mathcal{T} \}
\]
```

[在 Overleaf 中打开此示例](https://www.overleaf.com/docs?engine=pdflatex\&snip_name=Maths+typeface+example\&snip=%5Cdocumentclass%7Barticle%7D%0A%5Cbegin%7Bdocument%7D%0ALet+%5C%28+%5Cmathcal%7BT%7D+%5C%29+be+a+topological+space%2C+a+basis+is+defined+as%0A%5C%5B%0A+%5Cmathcal%7BB%7D+%3D+%5C%7BB_%7B%5Calpha%7D+%5Cin+%5Cmathcal%7BT%7D%5C%2C+%7C%5C%2C++U+%3D+%5Cbigcup+B_%7B%5Calpha%7D+%5Cforall+U+%5Cin+%5Cmathcal%7BT%7D+%5C%7D%0A%5C%5D%0A%5Cend%7Bdocument%7D)

此示例生成如下输出：

![数学字体示例](/files/5f0656a87d1c71a526d4b40069197ab9d7d5f6de)

使用某些数学字体样式需要将以下一行 `\usepackage{amssymb}` 添加到文档导言区：参见 [`amsfonts` 宏包](https://ctan.org/pkg/amsfonts) 以获取更多信息。

## 仅含大写字母的字体

有些字体只支持有限数量的字符；这些字体通常表示某些特殊集合。例如，要用黑板粗体字体显示 R，可以使用 `\(\mathbb{R}\)` 来生成 $$\mathbb{R}$$。下面的示例展示花体、德式花体和黑板粗体字体：

```latex
\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{document}
\begin{align*}
RQSZ \\
\mathcal{RQSZ} \\
\mathfrak{RQSZ} \\
\mathbb{RQSZ}
\end{align*}
\end{document}
```

[在 Overleaf 中打开此示例](https://www.overleaf.com/docs?engine=pdflatex\&snip_name=Using+different+math+fonts\&snip=%5Cdocumentclass%7Barticle%7D%0A%5Cusepackage%7Bamsmath%7D%0A%5Cusepackage%7Bamssymb%7D%0A%5Cbegin%7Bdocument%7D%0A%5Cbegin%7Balign%2A%7D%0ARQSZ+%5C%5C%0A%5Cmathcal%7BRQSZ%7D+%5C%5C%0A%5Cmathfrak%7BRQSZ%7D+%5C%5C%0A%5Cmathbb%7BRQSZ%7D%0A%5Cend%7Balign%2A%7D%0A%5Cend%7Bdocument%7D)

此示例生成如下输出：

![更改数学排版字体](/files/9f65c6896d88706130d607fe2335d1a4598a5003)

## 其他数学字体

可以为整个数学表达式设置不同的字体族：

```latex
\begin{align*}
3x^2 \in R \subset Q \\
\mathnormal{3x^2 \in R \subset Q} \\
\mathrm{3x^2 \in R \subset Q} \\
\mathit{3x^2 \in R \subset Q} \\
\mathbf{3x^2 \in R \subset Q} \\
\mathsf{3x^2 \in R \subset Q} \\
\mathtt{3x^2 \in R \subset Q}
\end{align*}
```

[在 Overleaf 中打开此示例](https://www.overleaf.com/docs?engine=pdflatex\&snip_name=Using+a+font+family+for+mathematical+expressions\&snip=%5Cdocumentclass%7Barticle%7D%0A%5Cusepackage%7Bamsmath%7D%0A%5Cusepackage%7Bamssymb%7D%0A%5Cbegin%7Bdocument%7D%0A%5Cbegin%7Balign%2A%7D%0A3x%5E2+%5Cin+R+%5Csubset+Q+%5C%5C%0A%5Cmathnormal%7B3x%5E2+%5Cin+R+%5Csubset+Q%7D+%5C%5C%0A%5Cmathrm%7B3x%5E2+%5Cin+R+%5Csubset+Q%7D+%5C%5C%0A%5Cmathit%7B3x%5E2+%5Cin+R+%5Csubset+Q%7D+%5C%5C%0A%5Cmathbf%7B3x%5E2+%5Cin+R+%5Csubset+Q%7D+%5C%5C%0A%5Cmathsf%7B3x%5E2+%5Cin+R+%5Csubset+Q%7D+%5C%5C%0A%5Cmathtt%7B3x%5E2+%5Cin+R+%5Csubset+Q%7D%0A%5Cend%7Balign%2A%7D%0A%5Cend%7Bdocument%7D)

此示例生成如下输出：

![更改数学排版字体](/files/2fa51b28075ae9144bcd8e7a52610d2a4b94aeda)

在这种情况下，不仅字母，所有字符的外观都会改变；例如， `$\mathit{3x^2}$` 会将整个表达式斜体化，从而得到 $$\mathit{3x^2}$$.

## 进一步阅读

更多信息请参见

* [`amsfonts` 包文档](https://ctan.org/pkg/amsfonts)
* [数学表达式](/latex/zh-cn/shu-xue/01-mathematical-expressions.md)
* [下标和上标](/latex/zh-cn/shu-xue/02-subscripts-and-superscripts.md)
* [粗体、斜体和下划线](/latex/zh-cn/latex-ji-chu/03-bold-italics-and-underlining.md)
* [字体大小、字体族和样式](/latex/zh-cn/zi-ti/01-font-sizes-families-and-styles.md)
* [字体类型](/latex/zh-cn/zi-ti/02-font-typefaces.md)
* [文本对齐](/latex/zh-cn/ge-shi-hua/06-text-alignment.md)
* [LaTeX2ε 的不算太短的介绍](http://www.ctan.org/tex-archive/info/lshort/)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://ayakaleaf-pro.ayaka.space/latex/zh-cn/shu-xue/12-mathematical-fonts.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.