anonyfloss

I have learnt that, when I account for time spent auditing dependencies, writing my own implementations becomes quite attractive

Yes this is the way to go. As few deps as possible.

Try https://en.wikipedia.org/wiki/Elementary_Calculus:_An_Infini...

Generally most of these 'handwavy' notations are rigidly provable, but only under general assumptions, that might not be true in special cases.