Use "riemann" in a sentence

1. Mathematicians regard the validity (or not) of a theorem known as the Riemann hypothesis to be the most important unsolved question in mathematical theory

2. In 1859, Bernhard Riemann (Germany) put forward a hypothesis involving a convoluted mathematical entity called the Riemann zeta function

3. Riemann suggested that the zeroes of the zeta function all lie on a well-defined straight line