Diagram of <a href="https://en.wikipedia.org/wiki/cusp_catastophe" class="extiw" title="w:cusp catastophe">cusp catastophe</a> geometry in bifurcation theory.
<a href="//commons.wikimedia.org/wiki/User:Jheald" title="User:Jheald">Jheald</a>
Made in OpenOffice Draw, exported as SVG.