He had made advances in the areas of analysis, foundations and logic, made many contributions to the teaching of calculus and also contributed to the fields of differential equations and vector analysis.
Ta tegi edasiarendusi valdkondades, nagu analüüs, alused ja loogika, aitas kaasa matemaatilise analüüsi õpetamisele ning andis panuse veel diferentsiaalvõrrandite ja vektorite analüüsimisse.