Mathematical_fonts

Introduction

Some mathematical elements require typesetting using fonts containing characters/symbols with certain styles. For example, people are accustomed to using blackboard bold (such as ℝ) to represent real numbers, or calligraphic fonts (such as 𝒯) to represent topological spaces. This article starts with the following example to illustrate how to use different font styles when typesetting mathematics.

Let \( \mathcal{T} \) be a topological space, a basis is defined as
\[
 \mathcal{B} = \{B_{\alpha} \in \mathcal{T}\, |\,  U = \bigcup B_{\alpha} \forall U \in \mathcal{T} \}
\]

Capital Letters

Some fonts only support a limited number of characters; these fonts typically represent some special sets. For example, to display ℝ in blackboard bold, you can use \(\mathbb{R}\) to produce ℝ. The following example shows calligraphic, fraktur, and blackboard bold fonts.

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

Different Font Styles

The following example demonstrates various mathematical font styles:

\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*}

Summary

Mathematical fonts play an important role in typesetting mathematical documents. Different fonts convey different meanings and are used in specific contexts. The amsmath and amssymb packages provide comprehensive support for mathematical fonts in LaTeX documents.