# Environment \left| \right| and \left( \right) not working properly with fourier package

Currently I'm using fourier package to write mathematics documents

However, when I attempt to use \left| \right| to indicate the module of a vector, this is what I get. Also, when I use \left( \right) to indicate the angle between vectors, something strange also appear (see both of these in the following picture) This is a simplifed version of my whole document

\documentclass[12pt,a4paper,oneside]{book}
\usepackage{fourier}
\usepackage{amsmath,amssymb}
\usepackage{mathrsfs}
\usepackage{fancyhdr}
\usepackage{enumerate}
\usepackage[most]{tcolorbox}
\usepackage[tikz]{bclogo}
\usepackage{tabvar}
\usepackage{venndiagram}
\usepackage{pgfplots}
\usepgfplotslibrary{fillbetween}
\usetikzlibrary{patterns}
\pgfplotsset{compat=1.9}
\usepackage[top=2cm, bottom=2cm, left=2cm, right=1.5cm] {geometry}
\usepackage[hidelinks,unicode]{hyperref}

\usepackage{currfile}

\DeclareSymbolFont{largesymbols}{OMX}{yhex}{m}{n}
\DeclareMathAccent{\wideparen}{\mathord}{largesymbols}{"F3}

\begin{document}
Given two vectors $\vec{a}$ and $\vec{b}$ such that $\left| \vec{a} \right| = 2$,
$\left|\vec{b} \right| = 3$, $\left( \vec{a}, \vec{b} \right) = 60^\circ$.
Determine the value of $\left| \vec{a} + \vec{b} \right|$.
\end{document}


Do you have any idea why this is happening? Thank you for reading.

• Please post an example code that enables others to reproduce the problem. It's hard to diagnose from screenshots. – Ian Thompson Jun 21 '18 at 21:54
• Sorry for that. I added a simplifed version of my document – ElementX Jun 21 '18 at 22:13
• You are redefining the largesymbols font. Don't do this with fourier. – Ulrike Fischer Jun 21 '18 at 22:17

## 1 Answer

You're confusing fourier by changing the largesymbol font. Just use a different name.

\documentclass[12pt,a4paper,oneside]{book}
\usepackage{fourier}
\usepackage{amsmath,amssymb}
\usepackage{mathrsfs}
\usepackage{fancyhdr}
\usepackage{enumerate}
\usepackage[most]{tcolorbox}
\usepackage[tikz]{bclogo}
\usepackage{tabvar}
\usepackage{venndiagram}
\usepackage{pgfplots}
\usepgfplotslibrary{fillbetween}
\usetikzlibrary{patterns}
\pgfplotsset{compat=1.9}
\usepackage[top=2cm, bottom=2cm, left=2cm, right=1.5cm] {geometry}
\usepackage[hidelinks,unicode]{hyperref}

\usepackage{currfile}

\DeclareSymbolFont{yhlargesymbols}{OMX}{yhex}{m}{n}
\DeclareMathAccent{\wideparen}{\mathord}{yhlargesymbols}{"F3}

\begin{document}

Given two vectors $\vec{a}$ and $\vec{b}$ such that $\left| \vec{a} \right| = 2$,
$\left|\vec{b} \right| = 3$, $\left( \vec{a}, \vec{b} \right) = 60^\circ$.
Determine the value of $\left| \vec{a} + \vec{b} \right|$.

$\wideparen{ABC}$

\end{document} By the way, the output shows you shouldn't use \left and \right in those situations.

Here's the output with \left and \right omitted. 