- (archaic, calculus) calculus
- 1816: John Playfair, Dissertation on the Progress of Mathematical and Physical Science since the Revival of Letters in Europe
- (mathematics, analysis) a systematic employment of infinitesimals that reduces calculus to algebra; nonstandard analysis.
- 1998: John L. Bell, A Primer of Infinitesimal Analysis.
- 2002: E.I. Gordon, A.G. Kusraev, S.S. Kutateladze, Infinitesimal Analysis