If you can use the stix package (or unicode-math), then the symbol is available as \approxident. Note however that \usepackage{stix} in a pdfLaTeX document will change all math symbols. Also importing only the symbol from the STIX fonts might give one that's not compatible with your sy...
\begin{align*} & F_{in} = \int \frac{\partial Q}{\partial s}|_{in} ds, F_{out} = \int \frac{\partial Q}{\partial s}|_{out} ds \\ & S_{in} \equiv \frac{F_{in}}{Q_{in}}, S_{out} \equiv \frac{F_{out}}{Q_{out}} \end{align*} However, the result of ...
JyNIgate is kind of a bridge between CPython and JyNI. JyNI contains lots of code that comes from CPython, but it is too different from CPython to be maintained as a fork. JyNIgate is a fork of CPython that contains some JyNI-specific changes (note that