In 1872 he became Professor of Algebra and Calculus of the Politecnico di Milano University. From 1879 he was professor of mathematics at the Reale Istituto Tecnico Superiore, where, in 1901, was affixed a plaque that remembers him.
He was also a corresponding member of Istituto Lombardo.
He made contributions to the theory of functions of a real variable and to Fourier series. For example, Ascoli introduced equicontinuity in 1884, a topic regarded as one of the fundamental concepts in the theory of real functions.[2] In 1889, Italian mathematician Cesare Arzelà generalized Ascoli's Theorem into the Arzelà–Ascoli theorem, a practical sequential compactness criterion of functions.[3]
Tricomi, G. F. (1962). "Giulio Ascoli". Matematici italiani del primo secolo dello stato unitario (Italian mathematicians of the first century of the unitary state). Memorie dell'Accademia delle Scienze di Torino. Classe di Scienze fisiche matematiche e naturali, series IV. Vol. I. p. 120. Zbl0132.24405. Archived from the original on 28 July 2012. Retrieved 31 July 2010.{{cite book}}: CS1 maint: bot: original URL status unknown (link)(in Italian). Available from the website of the.