FTP name this man who, when Gauss asked him to  discuss the foundations of geometry in a lecture, developed a consistent non- Euclidean elliptic geometry.
At fourteen Schmalfuss, the director of his school, decided that his pupil could learn no more from him and lent  him a copy of Legendre's Theory of Numbers, an 859 page work that he mastered in just six days. In a  probationary essay on Dirichlet's condition for the representability of a function by its Fourier series he developed a  new and rigorous definition of the integral as an operator. FTP name this man who, when Gauss asked him to  discuss the foundations of geometry in a lecture, developed a consistent non- Euclidean elliptic geometry.
At fourteen Schmalfuss, the director of his school, decided that his pupil could learn no more from him and lent  him a copy of Legendre's Theory of Numbers, an 859 page work that he mastered in just six days.
Georg Friedrich Bernhard Riemann