[Tex/LaTex] Different appearance of the `sim’ in \sim and \succsim

Question

I have to write a LaTeX document using a particular style using the preamble below. When I use binary relation \sim, it looks very different (much flatter) than the corresponding part of \succsim.

How can I make the output of \sim look more like the corresponding tilde in \succsim?

MWE and its output below.

\documentclass{standalone}
\usepackage{lmodern}
\usepackage{fourier}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{microtype}
\usepackage{amssymb}

\begin{document}
$\succsim \quad \sim$
\end{document}

Answer 1

You should not load fourier and lmodern together. Moreover, the documentation of fourier tells you that amssymb should be loaded before it.

Your problem is that fourier has a very distinctive “sim” sign, so you need to override it in order to use the Computer Modern or Latin Modern symbol.

\DeclareSymbolFont{CMsymbols}{OMS}{cmsy}{m}{n}
\SetSymbolFont{CMsymbols}{bold}{OMS}{cmsy}{b}{n}
\DeclareMathSymbol{\sim}{\mathrel}{CMsymbols}{"18}

Full example:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{amssymb}
\usepackage{fourier}
\usepackage{microtype}

\DeclareSymbolFont{CMsymbols}{OMS}{cmsy}{m}{n}
\SetSymbolFont{CMsymbols}{bold}{OMS}{cmsy}{b}{n}
\DeclareMathSymbol{\sim}{\mathrel}{CMsymbols}{"18}

\begin{document}
$a \succsim b \sim c$
\end{document}