Chapter 10 Differential calculus

She [Leni Pökler] even tried, from what little calculus she’d picked up, to explain it to Franz as $\Delta t$ approaching zero, eternally approaching, the slices of time growing thinner and thinner, a succession of rooms each with walls more silver, transparent, as the pure light of the zero comes nearer.

— Thomas Pynchon, Gravity’s Rainbow. Usually somewhere around p. 160 (depending on edition)