"Complex analysis" (where complex means "having both real and imaginary parts") is hard to justify because we get our math from the world, where many is always many and not one.
Hegel had interesting things to say on limits. Google it.
"The linear series that in its movement marks the retrogressive steps in it by knots, but thence goes forward again in one linear stretch, is now, as it were, broken at these knots, these universal moments, and fall asunder into many lines, which, being bound together into a single bundle, combine at the same time symmetrically, so that the similar distinctions, in which each separately took shape within a sphere [Parmenides's One], meet again."
Phenomenology of Mind
According to Nietzsche, Hegel "systematized the riddle" of being and nothingness thru teaching that all is "obscure, evolving, crepuscular, damp, and shrouded".
Marx wrote:
"First making the differentiation and then removing it therefore leads literally to nothing. The whole difficulty in understanding the differential operation (as in the negation of the negation generally) lies precisely in seeing how it differs from such a simple procedure and therefore leads to real results."
Negations of nothing!
"Marx recognized the differential equation as an ‘operative formula’ — ‘a strategy of action’ which, when it arises, constitutes a reversal of the differential process, since the ‘real’ algebraic processes then arise out of the symbolic operational equation, which originally itself arose out of a ‘real’ algebraic process... The German mathematician Gumbel led a team to decipher them [Marx's 1000 pages of mathematical manuscripts] and published a report in 1927 listing the wide range of subjects dealt with." marxist dot com
This might be relevant, since against we understand math through the world:
http://www.hawking.org.uk/godel-and-the-end-of-physics.html?fbclid=IwAR297vm3qpeViCnrXcGXBuRo-PXCEXIOcUiQxlFQWk1e20Xvu-e90P_OhrA
Russell talked about Zeno's paradoxes in lectures and in books. He said that they had extreme subtlety. Ironically, you have to have an asymmetry between the hemispheres in order to see this