Louis François Antoine Arbogast

He wrote on series and the derivatives known by his name: he was the first writer to separate the symbols of operation from those of quantity, introducing systematically the operator notation DF for the derivative of the function F.[3] In 1800, he published a calculus treatise[4] where the first known[5] statement of what is currently known as Faà di Bruno's formula appears, 55 years before the first published paper[6] of Francesco Faà di Bruno on that topic.

Arbogast submitted an essay to the St Petersburg Academy in which he came down firmly on the side of Euler.

Arbogast won the prize with his essay, and his notion of discontinuous function became important in Cauchy's more rigorous approach to analysis.

In 1789 he submitted in Strasbourg a major report on the differential and integral calculus to the Académie des Sciences in Paris which was never published.

The formal algebraic manipulation of series investigated by Lagrange and Laplace in the 1770s was put in the form of operational calculus by Arbogast in 1800.